Cai

Because there’s always a high chance of them having a baby and I love babies in manhwas except if they’re straight cause what’s the point heteros already can have babies in real life

Mpreg

Correct, Mpreg and men suffering instead of women

that and because I just wanna see pretty men get pregnant from doing the fwop fwop too hard (≧∀≦)

I personally like the fated mates part where they bond and can't cheat (both sides Alpha and Omega) It's a plus when there's a cute baby
What I don't like.. the part where omegas are treated as nuisance and something inferior. Prostitutes, poor, debt, needs sponsors, rape, SA etc.

I like the men being reduced to whiny messes, submitting to pleasure, the visual of them leaking so hard it not only pools on the underwear but drips on the floor is pretty nice , you can apply por logic (dick goes in hole no preparation) without it bring cringy AND you can detach sex from irl sexual attraction and romance and reduce it to pleasure and mating instinct (so despite how amatonormative it is, if you just want smut, it does a great job)

Mainly bcs of mpreg. From the root word 'Omega' who is commonly depicted as someone that 'can be impregnated' regardless of primary gender.