In general I try to stay positive when it comes to smash ultimate, given the amount of love and work and effort the smash team is putting into it, but now I'll reverse the roles and take the place of the critic
This brings me to my biggest problem with ultimate and smash in general, which is there nerfing habits.
With every new title, comes balance changes. And, every time, the charecters in every game are last title high tiers. Why? High tiers are mI'd tiers, with one or two things exceptionally broken. Ex. Sonic and spin dash. This way, the community complains the heck out of those single aspects, (though framed in that light it's a community issue but whoo that's not a discussion I want to have), and the developers, wishing to show the community their voices were heard, nerd those parts to pieces. This makes them completely unviable, once again Ex. Sonic, and forces the community that has already squeezed all they can out of there high-tier main in efforts to compete with top tiers to migrate or stop placing as well in tourney. However, the top tiers then become high-tier, and the cycle starts al over again. And, to top it off, it's not buffed low/mid/bottom tiers that replace high tiers, it's usually newcomers, newer is better meta, where you get you two or three games in the spotlight, then your done.
I obviously made a lot of generalizations, for instance fox is an exception to almost everything I said, but that dosen't really invalidate my points.