Actually there are not “fated mates” in this universe , Grayson is more like looking for his soulmate( in this universe it doesn’t exist a “one and only” like there are in some omegaverses) So don’t take the concept of “fated mates” as relative. Why does he think his soulmate is an omega and can’t be a beta or alpha is because his own perception . He actually idolizes his parents relationship so he is looking for something like that.

Does it make sense for a beta to have a fated mate? Now that I think about it, why does fated mates even exist in omega-verse, shouldn’t everyone have one?