Maybe you, as one of the old and experienced users of this forum, are not here to gain knowledge, but there will always be "newbies" (new bitcoin followers) in the world who will come here specifically for knowledge. And also for advice and help, especially if the questions concern the technical direction. Old users also need a forum in order to share their experience and knowledge, when all the experienced users leave the forum (for one reason or another), who will remain the bearer of knowledge?

But in general, a forum is a forum for communicating and exchanging information first and foremost. This is the most important thing, and under what "sauce" (incentive in the form of signatures and bounties) this happens is not so important. What is important is that the forum continues to "live" and communication here doesn't stop.

P.S. Bitcointalk can't be unrelated to money, because bitcoin is primarily money (at least, that's how it was intended).