I suppose in the beginning of the decade, when crypto and bitcoin weren't well-known, bitcointalk was the hub to join in order to understand and innovate crypto... but back then the only people getting into bitcoin were coders, deep web enthusiasts, and some people who were bore. So it was very niche.
I think that the biggest problem here is that most of the topics there are focused on earning money through signature campaigns and bounties (posted by users who's post quality is terrible) or on complaining about merit which as far as I noticed, was introduced at the beginning of this year. I agree with the OP.