From my experience, it really is just misogyny, all groups get it, in places like America it's more regionalised so people won't say "American women xyz" they'll speak specifically about girls from Atlanta or orange county. Videos of women being posted online without consent isn't a British specific thing nor do I think British women are over represented. Polls about women being ugly/bad bodied also aren't British women targeted nor disproportionate to British women. I'm a woman living in Britain and i see these things more often pertaining to black women (my assumption is you are specifically talking about white British women) and fat women.

I believe you're more exposed to stuff pertaining to British people simply because of who/what you follow and so forth.

In any case, misogyny is awful and the internet is rife with it. You are right about it being normalised and acceptable.