You joined Bitcointalk in late 2017, and you think the current state is worse? Bruh. If you think threads right now are rubbish, what more in late 2017? I'd say Bitcointalk's current state is great compared to the past as a lot of people stopped due to the merit system and a lot of people capitulated due to bitcoin's drop in price.
you forgot two major changes:
1. slow death of ICOs (aka scams) which practically put an end to a huge number of spammers trying to get some tokens for the "work" they were doing.
2. end of 2 major Yobit spam campaigns which didn't have any cap for number of users and led to a lot of alt account wake ups and mass spam.