For niche topics it can be quite good. I have maybe 30 active niche topics with anything from a few thousand to several million subscribers where the discourse is civil and useful, most of the time. Good moderation seems key.
I also find Reddit good- but given I mainly follow subreddits focused on PC hardware, I'm less concerned. I would never go to Reddit for discussion about political or controversial topics where botting would be a target.
But not just due to astroturfing, but their users are also just pretty crazy and exist in a extremely narrow bubble.
