no I don't think that more of a omegaverse thing because even in normal bls you can see how they make the top character "masculine/stong" whereas the bottom character are usually more "feminine/weak", I mean there is nothing wrong with a feminine man but after readings some more bls you can see how the author are USUALLY straight women who tries to fit a heteronormative role in a gay relationship which is just fetishizing them
i mean if you're only finding dynamics like that i think it's partly on you, with all due respect. like off the top of my head there's under the green light, shutline, full volume, between fate and fortune, miscreants and mayhem, lucky paradise, legs that won't walk... it's not too hard to find masc bottoms.
"mom" "daughter-in-law" and that is a grown ass man