It seems pretty reasonable overall, although I do have a few objections (I won't bother with tiers below C-tier). To start off, Zero Suit Samus could probably drop a few spots. If we go by Nairo's ZSS MU chart, we see that ZSS loses a bunch of MUs (
https://image.prntscr.com/image/F8yxwgMcRd_BFlRDIhkgmQ.png), and most of the MUs that she wins are not super relevant. She's still a good character though and could very well be top 10, but #6 seems a bit too high for her, in my opinion.
I would say that Mario and Marth are too high, though it depends on how you view their MU charts, I suppose. I believe that Mario loses to Cloud, Marth/Lucina, Corrin, Sonic (potentially -2), Bayonetta, and potentially Donkey Kong. He doesn't win against anyone in top 15 either, aside from Pikachu (though you didn't put Pikachu in top 15 for some reason). Marth should be next to Lucina (maybe they both should move up a bit, I'm not sure, but they're probably worse than Corrin anyway).
Speaking of Corrin, I do believe that she's top 10. She only loses 3-4 MUs (Diddy Kong, Fox, Sheik, and maybe Cloud), wins against most characters in high tier and nearly all mid tiers and all low tiers, and also potentially beats Mario and Rosalina. She should at least be above Mario and Marth.
Pikachu should be a bit higher, I believe. I assume you're mainly rating this as a solo viability tier list and don't take counter-pick value into account? Meta Knight has pretty good counter-pick value, but his solo viability is likely worse than Pikachu's, so Pikachu should be higher.
Luigi is, I believe, somewhat overrated. He likely loses -2 to Mewtwo and Rosalina & Luma and has a bunch of -1 MUs, and doesn't really win all that notable MUs. Captain Falcon is in a similar position, losing to all characters in top 15 aside from Corrin (who he goes even with) and potentially Rosalina. Having a rather bad MU vs Bayonetta doesn't help his viability.
As for C tier, why are Bowser and DK that high? Their MU charts are pretty mediocre. How can they be high tier characters when they lose pretty hard to Bayonetta, Rosalina, Sonic (at least Donkey Kong), and Zero Suit Samus, while also slightly losing to nearly every top 20 character? They had some niche use as counter-picks because their kill confirms are so good, but really, these characters are not really that solo viable. Actually I think Bowser's position relative to most other characters is pretty fine, and Donkey Kong should probably be next to him. They should drop down to mid tier though. I also think calling the #28th character "high" tier is a bit strange. 28/55 is not high, it's just somewhat above the middle.