I think when we talk about how the "vast majority" of the church has understood the Greek word behind the English rendering "perish" (e.g. Jn.3:16), it has not meant endless annihilation for the past 2000 years except to a minority. The vast majority have not taken the word to mean annihilation, let alone endless annihilation.
Permanence has nothing to do with the word apollumi rendered "perish", "lost", "destroy", "lose", "ruin", "die", etc in the Scriptures. A person, e.g. Lazarus, could "perish" (i.e. die) & be raised back to life again in a few minutes, hours or days. The duration of "perish" was hardly permanent. The word itself tells us nothing of how long the thing or person etc shall "perish", be "lost", "ruined", "destroyed", etc.
In the case of 2 Thess.1:9 the context does tell us how long the "destruction" will be. It is aionion, eonian, that is pertaining to, or related to, an eon or eons. Certainly not something that need be everlasting, but may very well last a long, long time.
2Thess.1:9 Who, indeed, a penalty, shall pay—age-abiding destruction from the face of the Lord and from the glory of his might— (Rotherham)
9 who shall incur the justice of eonian extermination from the face of the Lord, and from the glory of His strength" (CLNT)
who shall suffer justice -- destruction age-during -- from the face of the Lord, and from the glory of his strength, (2 Thess 1:9, YLT)
A recent new translation by EO scholar David Bentley Hart reads: "Who shall pay the just reparation of ruin in the Age, coming from the face of the Lord and the glory of his might" (A Translation: The New Testament, 2017, Yale University Press).
Regarding the mistranslation "everlasting" or "eternal" in 2 Thess.1:9: "166 aiṓnios (an adjective, derived from 165 /aiṓn ("an age, having a particular character and quality") –
properly, "age-like" ("like-an-age"), i.e. an "age-characteristic" (the quality describing a particular age);..."
https://biblehub.com/greek/166.htm
A Greek lexicon at the following url states re the Greek word olethron ("destruction") at 2 Thess.1:9:
"...Hierocles 14, 451b has the thought that the soul of the sinner in Hades is purified by the tortures of hell, and is saved thereby..."
https://translate.academic.ru/ὄλεθρος/el/xx/
As does p.702 of "A Greek–English Lexicon of the New Testament and Other Early Christian Literature, 3rd ed. (BDAG)":
A Greek–English Lexicon of the New Testament and Other Early Christian Literature, 3rd ed. (BDAG)
https://www.amazon.ca/Greek-English-Lexicon-Testament-Christian-Literature/dp/0226039331
Compare that above statement to:
"In Ancient Greek mythology, Olethros was the personification of Havoc and probably one of the Makhai. Olethros translates roughly in ancient Greek to "destruction", but often with a positive connotation, as in the destruction required for and preceding renewal."
Here we see "destruction" is for the good of the person:
... deliver such a one to Satan for the destruction of the flesh, that his spirit may be saved in the day of the Lord Jesus. (1Cor 5:5)
He who is finding his soul will be destroying it, and he who destroys his soul on My account will be finding it. (Mt.10:39)
Here we see destruction was temporary:
Jesus answered them, "Destroy this temple, and I will raise it again in three days." (Jn.2:19)
"Does the eschatological destruction of 2 Thessalonians 1:9 exclude all redemptive possibilities? Nothing in the text requires such a reading." Continued at:
https://afkimel.wordpress.com/2015/02/22/book-review-the-inescapable-love-of-god-part-5/
http://evangelicaluniversalist.com/forum/viewtopic.php?f=50&t=213
Further re 2 Thess.1:9, Jason Pratt said:
"Which definitely refers to hopeful punishment (and expected salvation in the same day of the Lord to come), not annihilation, when Paul uses it to talk about handing the Stepmom-Sleeping Guy over to Satan for the whole-destruction of the flesh in 1 Cor 5:5.
"Paul compares it to a birth-pang, which is dangerous but hardly hopeless annihilation (and is generally regarded as very hopeful) at 1 Thess 5:3 (talking about the same day to come).
"Paul uses the term to describe people killed by God in the past at 1 Cor 10:10, which can hardly be annihilation unless the resurrection of the evil as well as the good is denied.
"2 Thess 1:9 uses phrases similar to those found in Isaiah 2, talking about the same coming event, which is part of a block of prophecy where those wholly ruined aren't annihilated, but eventually repent of their sins and go to the "survivors" of God's wrath to be reconciled to God, which God accepts washing them clean with spirit and with fire. (Isaiah 4.) Again, far from a result of hopeless annihilation.
"2 Thess 1 is actually one of my scriptural testimonies 'for' universal salvation."
http://evangelicaluniversalist.com/forum/viewtopic.php?f=11&t=4087
Lamentations 3:22 and 3:31-33, The steadfast love of the Lord NEVER ceases, his mercies NEVER come to an end. . . .
Lam.3:31 For the Lord will NOT cast off FOR EVER:
32 For if He causes grief, Then He will have compassion According to His abundant lovingkindness. 33 For He does not afflict willingly Or grieve the SONS OF MEN.…
Rom 5:18 Consequently, then, as it was through one offense for ALL MANKIND for condemnation, thus also it is through one just act for ALL MANKIND for life's justifying."
Rom 5:19 For even as, through the disobedience of the one man, THE MANY were constituted sinners, thus also, through the obedience of the One, THE MANY shall be constituted just."
Paul makes a parallel between "the many" who were condemned & sinners and those who will be justified & constituted just.
“In Romans 5, the justification is co-extensive with the condemnation. Since all share in one, all share in the other. If only a certain portion of the human race had partaken of the sin of Adam, only a certain portion would partake of the justification of Christ. But St. Paul affirms all to have been involved in one, and all to be included in the other.”
Therefore there is salvation after death. And corrective punishment.
https://www.tentmaker.org/books/hope_beyond_hell.pdf
Jesus shall see of the travail of His soul & be satisfied. Not satisfied a little bit, but the vast majority fried alive forever.
"He shall see of the travail of his soul, and shall be satisfied: by his knowledge shall my righteous servant justify many; for he shall bear their iniquities." (Isa.53:11).
For how "many" (not few) did He "bear their iniquities"? All.
https://www.tentmaker.org/books/hope_beyond_hell.pdf
Who is the author of the "King James Dictionary"? What are his qualifications in Greek? If it was published in 1828, can we consider it up to date with the latest Greek scholarship:
https://www.studylight.org/dictionaries/kjd.html
OTOH here are what some Greek scholars say:
"There is nothing in the word that necessitates ἀπόλλυμι means a permanent and total destruction.":
https://www.billmounce.com/monday-with-mounce/does-ἀπόλλυμι-mean-“destroy”
"The idea is not extinction but ruin, loss, not of being, but of well-being. This is clear from its use, as, e.g., of the marring of wine skins,
Luke 5:37; of lost sheep, i.e., lost to the shepherd, metaphorical of spiritual destitution,
Luke 15:4,6, etc.; the lost son,
Luke 15:24; of the perishing of food,
John 6:27; of gold,
1 Peter 1:7. So of persons,
Matthew 2:13, "destroy;"
Matthew 8:25, "perish;"
Matthew 22:7;
Matthew 27:20; of the loss of well-being in the case of the unsaved hereafter,
Matthew 10:28;
Luke 13:3,5;
John 3:16(
John 3:15 in some mss.);
John 10:28;
John 17:12;
Romans 2:12;
1 Corinthians 15:18;
2 Corinthians 2:15, "are perishing;"
2 Corinthians 4:3;
2 Thessalonians 2:10;
James 4:12;
2 Peter 3:9."
https://studybible.info/vines/Destroy, Destroyer, Destruction, Destructive
The first meaning above is "1. To die; to lose life in any manner". This recalls the prodigal son's loss of life. He is spoken of as "dead" & "lost"(apolummi). Not permanently or eternally, but only until he was later found & alive. He was never endlessly annihilated or ceasing to exist.
Man is more than just dust, earth, water, & material substances. He is made in the image & likeness of God & has a soul & spirit.