Funny you should say that. Because the way it is used now is pretty much what the variants forum was originally designed for. (At that time chess.com did not support chess variants for playing.)
At some point people suddenly started to abuse the forum for playing games. A lot of people complained about that, because there were so many games, and these were so frequently posted in, that any discussion about chess variants (newly invented or not) would quickly be pushed several pages down, so that no one would see them. At that time it was suggested a separate forum section should be made for playing (variant) games. Nevertheless the game playing continued here.
But apparently it has mostly stopped now.
You cannot blame Kenta for not many others posting here. If he would not post here that still would not make anything you (apparently) would like to see appear here. Although I agree with your criticism that many of the games he presents are not chess variants at all, but completely unrelated games. It is not clear what you mean by "meaningful discussion". I would not consider topics were people just post moves and images of positions "meaningful discussion". These are just games. (And often of appalling quality...)
Thanks for listening to my rant. Post what you think we should do, anyone who is actually part of this variant community.
P.S. This is not meant to discourage or insult you, @Kenta2022, but I think our variants forum could be a lot better.