Most fighting games outside of the big mainstays don't sell that well overall. I'm not surprised not a lot of people are talking about it.
Rollback netcode and crossplay is great, but when most people complain or talk about adding these, they want it for the franchises that they actually care about (IE Street Fighter, Tekken, Smash, etc.) A game doesn't sell alone based on having rollback/crossplay. A game sells by having interesting characters and decent foundational game mechanics. While this game might be technically outstanding, its roster of characters (mostly obscure) and Gougi system probably didn't attract players at launch, thus killing its momentum and preventing it from potentially picking up.
Still, while rollback/crossplay will certainly help the player base, I would be shocked if it ever manages to get big mainstay numbers of a player base.