Although Mario did very well at EVO, it was largely due to Ally's success with the character, as most of the Mario's on stream didn't get that far.
https://docs.google.com/spreadsheet...PwUQjQ-Ew0QyTc4/htmlview?usp=sharing&sle=true
https://docs.google.com/spreadsheet...tlxAZv5pv19QDHUtqR2Ddo06xy8/htmlview?sle=true
Compare this to Diddy Kong, who not only had more players on the stream than Mario, but he also gathered a lot more success as well.
I am of the firm belief that Mario is a Top 15 character at least, though Top 10 could be more suiting for him in most people's eyes. However, I highly doubt that he is a Top 3 character, or even a Top 5 character. And the biggest reason behind this is that he simply doesn't overwhelm most top tier characters. Plus, there are a good number of characters that have a slight edge against him within the upper tiers, as well.
Mario has a clear advantage against
![Megaman :4megaman: :4megaman:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
![Pikachu :4pikachu: :4pikachu:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
(
![Meta Knight :4metaknight: :4metaknight:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
?), but he has disadvantageous matchups against
![Sonic :4sonic: :4sonic:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
![Mewtwo :4mewtwo: :4mewtwo:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
![Rosalina :rosalina: :rosalina:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
and I think against
![Zero Suit Zamus :4zss: :4zss:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
too. He also has trouble against characters like
![Donkey Kong :4dk: :4dk:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
![Marth :4marth: :4marth:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
and possibly
![Corrin :4corrin: :4corrin:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
although they are a tier lower than the other characters he has trouble against. And while
![Cloud :4cloud: :4cloud:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
![Fox :4fox: :4fox:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
are pretty even matchups, Mario's ability to easily edgeguard them is a large reason why he is able to keep relatively even matchups with those characters (same with Marth). Otherwise, they have strengths that hit Mario pretty hard, such as Cloud's/Marth's range or Fox's speed and CQC strength.
![Ryu :4ryu: :4ryu:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
is a similar case, although he has far more strength for Mario to worry about at the cost of being easier for Mario to deal with overall.
![Diddy Kong :4diddy: :4diddy:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
![Sheik :4sheik: :4sheik:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
are mostly even, though it could be said that Mario has a slight advantage against Sheik now.
Outside of the first two-three characters I mentioned though, Mario doesn't have a HUGE advantage against anyone in the top tiers, and there are a good number of checks and counters against him as well. And while this makes Mario's MU spread "well-rounded" overall within the high-top tiers, it isn't really that special when
![Diddy Kong :4diddy: :4diddy:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
![Sheik :4sheik: :4sheik:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
![Cloud :4cloud: :4cloud:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
![Mewtwo :4mewtwo: :4mewtwo:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
can boast similar claims and yet can have even better MU's and results. Diddy in particular, for sure. And while Sheik had a bit of a fall from grace, Cloud did pretty poorly at EVO, and Mewtwo has a much smaller player base; I feel as though that all four of them are stronger than Mario as a whole/overall.