If you think about it psychologically I think it's really just an extension of the mean girl high school attitude that these places facillate.
Since girls on these platforms can all look as pretty and young as they want the usual hierarchy for social dominance that exists is side stepped. In such an environment the only way for a girl to achieve social dominance is to gossip. This intensifies the social infighting of all women which you'd usually see only amongst young girls.
I think toxic girls maybe attracted to these environments since it's a place where that behavior is rewarded. A lot more so then their real lives if their not pretty, successful, or have strong community irl.
Minka for example is that loser she insults other of being. She rented an apartment with a roommate who literally shitted in her shower, she only managed to afford a house now at age 45-55, she works a low paying job, and she has no romantic partner.