The 2019 GOTY Awards

[Phoenixmgs_v1legacy]

"Literally what reason does Smash even have to release a NEW game"

i just gave you a reason.

That could literally just be patched in, be a user mod, or be in-game cheats that games used to have (and some still do) back in the day or simply gameplay sliders that sports games have.

your grappling hook in Monster Hunter could also just be "patched in".

big whoop!

It was via expansion, there's no Monster Hunter World 2 out there.