Where did you get that info from?
From the Silmarillion. Confirmed in the video I shared to y’all lol.
Y’all are confusing differences in authorial representation with authorial intent.
“Acnologia destroyed a continent, Ancalagon never destroyed a continent, therefore Acnologia destroys him”
This is completely ignoring the fact that the entire idea behind Ancalagon was that he was the single greatest weapon possessed by a literal god (Morgoth), Ancalagon being so powerful that the armies of several god-like entities were completely smashed as soon as Morgoth released Ancalagon, and it literally took another god-like entity crashing a Galaxy-traversing Star into his chest to defeat him.
You are comparing a being who overwhelmed multiple gods in succession, and who it was pretty much a miracle that those gods actually defeated him at all, to some Shonen Dragon Ant, and saying the Ant wins because the writer of Fairy Tale wanted to draw him destroying a continent to compete with One Piece or whatever the hell purpose Acnologia serves in his series lol.
Authorial intent my guys. One of these beings was created to overwhelm several gods simultaneously.