I really wish I had a time machine where I could go to the future and ask them what the general reasons were for this social development.
I think I had this exact thought yesterday. In the past, there's been hints that appear within just a few months if you're looking.
Most of the explanations posted aren't very convincing. If it's just a daddy figure or toxic masculinity or just personal affirmation that's not new and should have applied all along. The YouTube algorithm could be part of it, but then you just get a question about why the YouTube algorithm was pushing that.
A random theory, just based on something I read recently: looksmaxxing is becoming a big thing, which is itself a sign of equality in that the burden for being attractive is now going both ways. Paradoxically, the new cohort of men with body image issues is very vulnerable to radicalisation by the manosphere.
It'd be kind of surprising if that was the whole thing, though...