I have had similar thoughts, I think the answer ultimately lies in active mods that can really get to know a community and it’s users and identify when users are pushing a narrative even if they can’t confirm if they are a bot or not.
Also as @dessalines@lemmy.ml pointed out, user registrations. On startrek.website we have a question that is easy for a star trek fan to answer but not easy for a bot (although getting back to your concern, chatGPT probably would have no problem)
Actual Budget is software. It can be run on a home server if desired.