It doesn't have to be /b/ but in reddit's current form lack of free speech is a problem too. Power tripping mods are banning people for commenting at all in certain other subreddits. Politically inconvenient subs are getting qurantined if not outright banned. Similarly hateful but politically fashionable subreddits have been allowed to stay for years now. Politics permeates almost everything and if you don't share the ingroup opinion then it's not worth commenting. Granted a lot of this has to do with shitty mods and not reddit directly, but they aren't working to fix this either.
Obviously I can get around it with a VPN, but it seems most VPN IPs are shadowbanned by default, so you have to wait for every comment to be approved by mods.
The "crime" which earned this sanctioning? Spam, advertising, racism? Nope, I never posted anything like that. It was a sensible and very highly upvoted comment last year in support of the lab leak theory. The initial suspension PM from the admins openly linked to that comment as the reason for the ban.
That’s not free speech or effective censorship.
To me, the decline is an obvious Eternal September-like effect. The more popular it became, the more it attracted trolls, people with political agendas and other destructive forces. I think that sort of thing is as inevitable as programming languages ending in feature-bloat. I expect the same will happen to HN, even though I think the mods have done an incredible job so far and even though the atmosphere has shifted a bit I still enjoy the discussions here.