I think most of DK's matchups are near even. If not all of them lmao. I think solo-DK could win a national. I don't see any matchups that are unrealistic for him to win. Especially with the current stage banning system. A lot of his "bad" matchups have a few select stages where he either wins or it is even. Thus, if DK wins game 1 on an even stage, winning game 3 is cake most of the time. DK's very polarizing on the stages he's good at or bad at in most matchups like how he ****s on fox on FD but gets **** on by fox on stadium for example, and smashville is about even. If DK wins game 1 you're in for a rough ride due to his polarizing importance of having the CP advantage. People think I'm insane for saying solo-maining DK is viable, but I got fourth going ALL DK at one of the biggest and most stacked PM nationals EVER (flex zone) and I wasn't even that good back then so that says quite a bit about DK as a character in my opinion. My fundamentals were nowhere near "4th best" at that tournament so the sky's the limit if you consider how much room for improvement I had fundamentally at the time. If I could hand my punish game and DK experience to M2K, I'm pretty sure he'd win any national going all DK lol. Just like if he could hand me his fundamentals, I could win any national.
Argument against the few successful DK mains out there: "People just don't know the DK matchup. That's why they won"
Counterargument: The DK matchup is just watch out for grabs, bairs, up airs, and up b oos. Nothing else he has is really out of the ordinary. People saying they "don't know the matchup" is just johns or BS for the most part. Everyone knows the DK matchup after playing one or 2 games v.s. a solid DK, unless they are stubborn and don't adapt. He's one of the simplest characters in the game...if you're getting grabbed by DK you're just getting straight up outplayed because everyone knows not to get grabbed by DK.
Oh btw, I've stated this before but I figured I'd say it again. I was a solo-DK main but I wasn't "pessimistic" about the character by any means. I've only been playing him significantly less recently because of being bored of him. Due to his simplicity/repetetiveness, I found it pretty boring to solo-main DK for a long period of time. However, when I'm playin for dat W, DK's my main man. Who needs fun when you're makin da bills right?
Edit: BTW, yes you can count on me to show up whenever someone mentions the word "DK" to drop the truth smackdown. I have this sixth sense to know when and where people are talkin crap about my boy
Another Edit: I'm POOB