Personally, I think that the forum is much more transparent and that it is much easier to find some old and valuable information than on Discord or Telegram.
Even without a bounty programs or signature campaigns I'm sure this forum would still be important as a source of information and a place to socialize and chat.
However, I agree that the interest in this forum is decreasing and that there are fewer and fewer quality discussions.
I guess these are generational reasons and that the youngest members may not have the patience for long discussions on the forum and prefer to choose faster ways of communication through social networks, telegram groups etc.