Twitter/X is testing charging users $1/year with the idea that will keep out bots and spam. It’s an appealing idea, and charging definitely does introduce a “proof of work” that wasn’t there before, but the history of the web shows this is not really a big deterrent. Domains cost money, usually a lot more than a dollar a year, and millions are used for spam or nefarious purposes. The spammers obviously thought their benefit would be more than the cost of the domain, or they use stolen credit cards and identities. Charging may cause a short-term drop in bots while the bad guys update their scripts, but the value of manipulating X/Twitter is so high I imagine there is already millions of dollars being spent on it.
Long term to keep a platform healthy you really have to take a nuanced look at behavior and content, like Automattic does with Akismet, and have a fairly sophisticated trust and safety operation with great engineers. T&S is really important, not an enemy of progress, which would have been my chief edit to the otherwise exciting The Techno-Optimist Manifesto by Marc Andreessen. (If you missed Marc’s Why AI Will Save the World, that’s also an excellent read with dozens of references you can go down a rabbit hole with.)