I don’t think $5/month would stop the biggest offenders: content farms. I have reported dozens of accounts that have posted tens of thousands of tweets in the last few years. Accounts that spam US politicians with things like “I am a democrat and I will not vote for Biden because he is neo-Nazi…” and so on and so forth. Accounts that ruin the discussion, waste attention. Accounts that are obviously not authentic users but are a part of a foreign propaganda campaign. These accounts can afford to pay $5/month.
Content farms use a lot of accounts , they have to - impersonate realistic users easy to shadow ban block otherwise that $5/user/month quickly adds up.
The reason this idea does not go far is because the people who pay usually do not necessarily post good quality content , that degrades the quality of UGC and view time therefore ad revenue loss
Paying for a million fake users would be peanuts to a state actor. Russia, China, Saudi Arabia, etc... These users post on average 2 tweets per hour (my personal observation, not a reliable data point). A million users tweeting twice every hour that's 1.5B tweets. Per month.
I agree that introducing paid accounts would make it harder for content farms to exist - primarily due to the fact that they would need a very large number of bank accounts and/or payment cards. However I don't think it's a real solution to this problem. Maybe as a part of some holistic anti-bot system? Yes, that could work.
