It's probably because the amount of control Alphas/Omegas have during their ruts/heats depends of the author ig? Like the "rules" of omegaverse are kinda loose to be just a base to build on and each author decide how they want to shape them (like in some storied Alphas can get pregnant, in other they can't)
I would assume it depends on the story the manaka wants to tell and what is more conveniant
it depends but mostly it's about the affection they have towards their partner or the fact that they're scared of hurting their partner so instead they hurt themselves to gain consciousness. Most stories end up with the characters not knowing each other and than their first experience is basically them losing control. It's not the best trope but it is a popular one
as the previous person said, the only answer is because each one is made by a different author/mangaka and they make whatever they want to. imo if you're truly trying to give humans animalistic traits, then you mind as well fully commit to it. that said, not all omegaverse stories have to be centered around the alpha's uncontrollable desire due to infatuation with the omega as the genre allows for more interesting perspectives/takes on it, but alot of bad writers don't seem to understand this and its probably just easier to churn out
Ok kinda random but this js makes me think abt all the alphas in other mangas that "lost control" during freaky time or wtv that don't stop when told to... If kamiya could control himself against a disease thats literally telling him to js go by his instincts why couldn't all those other tops/alphas do that..? Until now ive always kinda defended them a bit since they were in a rut and weren't in control of themselves but that's basically what happened in this chapter and kamiya could control himself js after seeing hitomi giggle... do better guys
(also hitomi was so sexc..this chapter someone get him pregnant before i do...