There is one big problem with annihilationism - the elephant in the room if you will - with some/many/most of humanity reduced to permanent ashes, they still count as The Dead (not Grateful). On the other hand, the Bible states that Death is going to be destroyed.
So either,
annihilation is wrong
or
the Bible is wrong.
There is something wrong alright but it ain't the Bible or the person you are responding to.
Where does the Bible say that death is destroyed? I'm not saying it doesn't but you evidently do not know or understand the context or deliberately ignore it to push your agenda.
Revelation 21:4-8
4 And God shall wipe away all tears from their eyes; and there shall be no more death, neither sorrow, nor crying, neither shall there be any more pain: for the former things are passed away.
5 And he that sat upon the throne said, Behold, I make all things new. And he said unto me, Write: for these words are true and faithful.
6 And he said unto me, It is done. I am Alpha and Omega, the beginning and the end. I will give unto him that is athirst of the fountain of the water of life freely.
7 He that overcometh shall inherit all things; and I will be his God, and he shall be my son.
8 But the fearful, and unbelieving, and the abominable, and murderers, and whoremongers, and sorcerers, and idolaters, and all liars, shall have their part in the lake which burneth with fire and brimstone: which is the second death.
Vs. 4, "no more death." Vs. 5. "I make all things new." The UR mantra "all means all." But vs. 8 eight groups of people are thrown into the lake of fire and it is still the "second death."
Chap. 22 also has some bad news for the Hell No! crowd.
Revelation 22:11
11 He that is unjust, let him be unjust still: and he which is filthy, let him be filthy still: and he that is righteous, let him be righteous still: and he that is holy, let him be holy still.
Wait a minute everybody is supposed to be saved, here the unrighteous are left to their sins not somehow magically transformed into believers.
Revelation 22:14-15
14 Blessed are they that do his commandments, that they may have right to the tree of life, and may enter in through the gates into the city.
15 For without are dogs, and sorcerers, and whoremongers, and murderers, and idolaters, and whosoever loveth and maketh a lie.
Some have the right to the tree of life and entry into the new Jerusalem but some are still outside.
Revelation 22:18-19
18 For I testify unto every man that heareth the words of the prophecy of this book, If any man shall add unto these things, God shall add unto him the plagues that are written in this book:
19 And if any man shall take away from the words of the book of this prophecy, God shall take away his part out of the book of life, and out of the holy city, and from the things which are written in this book.
God said no more death in the previous chapter but here some people have their part in the book of life taken away.