I've had an idea for a while for a Mario-centric fighting game similar to Smash but focused exclusively on the Marioverse and its various branches. Due to being more contained in the Mario world, the characters can look more like their canon selves (rather than having that realistic edge they have in Smash) and it could be presented as a grand culmination of the legacy of Mario. I'd call it "Super Mario Smashers" with a clear reference to Smash Bros. in the name (even though the name "Super Smash Bros." oddly is a play on "Super Mario Bros." despite covering far more than just Mario)
One of the main reasons I want this is so we can have a Mario-centric game that covers the franchise as extensively as Smash does. A fighting game like Smash seems like the most ideal place to do that (since they've shown time and time again they aren't willing to do it with Mario Kart or other spinoffs of that nature)
I recently made an image depicting Mario characters from all over the franchise, while the roster might not be exactly this, it is indeed how expansive I'd like a game of this nature to be, perhaps even moreso (as I was limited to characters i could find a decent 3D depiction of)
But it is a large amount when compared to the other series, barring Fire Emblem.
It's why I don't want anymore Mario characters in smash, I'm good there.
On the subject of a dedicated Mario fighting game, the idea is amusing but due to how Mario always goes for simplified takes on whatever game genre it goes for it's hard for me to see how they could make such a game and still have it be worth playing compared to it's competition.