The truth is that bitcointalk is fundamentally different than other discussion forums due to the existence of signature campaigns and bounties, i.e., using avatars, personal text, and signature space to get paid for advertising. Since you generally get more advertising space the higher up you go in the ranks, if you're participating in a campaign or bounty or planning to, it's of great personal (and by that I mean financial) interest to get to the higher ranks.
It seems strange to me that it's seemingly become less important to members in the years that I've been here, because back in 2016-18 I think there were way more threads in Meta that dealt with ranking up. And after the merit system was introduced, all hell rained down in the Meta section because it suddenly became so much harder for Newbies to even become Jr. Members--and the shitposters who were used to just having to post and wait in order to rank up now were scratching their collective retarded heads, wondering how in the holy hell they were going to make posts good enough to earn merits.
They still haven't figured that one out. Probably never will.