What propagated simp culture?

I think it affects quite a few people's lives in a way, because it has a serious impact on the dating market. Are some of them bots? I noticed on the RateMe sub and the LooksMax sub, they are infested with what appears to be human male simps. All responding like 1100+ comments like "10 out of 10", "perfect", "dm me" etc. and it was already obvious that the girl who posted was conventionally attractive / even sometimes they were fake accounts where whoever or whatever was posting already knows the girl couldn't possibly be rated a 7 or below. How could these men lack such self awareness or awareness in general? If they are real human beings, I just feel bad for them. What do y'all think? What started this simp / OF promoting culture?