Isn’t this sort of what Twitter is trying with the $8/month thing? Forcing a cost to increase the barrier to posting as well as tie it to a human to go after when they do bad stuff.
This has always been a dilemma to me as identity proofing costs some money and that filters people out.
I remember when domain names went from free to $70 under network solutions. This was meant to be cheap but really limited people who could register domains.