I mean on the very surface they're similar but once you start digging at all the differences become pronounced.
D:OS2- Your ship gets wrecked and you wash up on the prison island you were going to anyway. You're trapped with many others in the same situation that aren't related to your party directly. Your powers are inhibited and you must figure out a way to break out of prison and free yourselves of the collars. Narratively speaking nothing is stopping the characters from just existing in captivity that way, Their status quo is the thing they're trying to escape from effectively.
BG3- You're captives who escape when your captors ship crashes, which immediately derails their plans. You're effectively free from that point and you're on the run. Only your party is in the same position as you are, I presume at least. You have an active pressure to act because there's a direct consequence for inaction.
And as for the collar and larva serving similar purposes, they serve similar structural purposes of tying the characters together like Wormerine says, but within their individual stories their purposes are very different.
