I always read KJV. For some reason this site does not auto-link Jude and 1 Peter... so I'll paste them right here:
Jude 6:7:
6 And the angels which kept not their first estate, but left their own habitation, he hath reserved in everlasting chains under darkness unto the judgment of the great day.
7 Even as Sodom and Gomorrha, and the cities about them in like manner, giving themselves over to fornication, and going after strange flesh, are set forth for an example, suffering the vengeance of eternal fire.
It says right there, "angels which kept not their first estate" ... "Even as Sodom and Gomorrha". Jude is comparing the Angels spoken of (the Fallen ones) to Sodom and Gomorrha in the sense that they "gave themselves over to fornication" and "going after strange flesh".
Now for 2 Peter 2:4-5 (sorry, I mis-typed in my earlier post, will edit later), says...
4 For if God spared not the angels that sinned, but cast them down to hell, and delivered them into chains of darkness, to be reserved unto judgment;
5 And spared not the old world, but saved Noah the eighth person, a preacher of righteousness, bringing in the flood upon the world of the ungodly;
Peter is obviously talking about "angels that sinned" that He threw into Hell.
I'm quoting a guy who IS knowledgable in Hebrew. Also, places like Biblehub support what I've said.
Yes, Noah was from the line of Seth. However, only Noah was saved and not the other "sons and daughters" that Seth had. This rules out the idea that "Sethites = Good, Cainites = Bad" because God killed them -all- except Noah and his family.
Some speculation, perhaps, but very logical one.