Zod never won a major and he doesn't even have that many placings so why is he guaranteed top 5 according to almost everyone?
I'm not completely sure where Zyphox stands on how good Flash's footsies are/what makes a character have good footsies. In a MU like Flash vs AM, I believe Flash gets heavily outfootsied because my best ranged attack in my B2 which is 15 start up frames and a mid compared to AMs B1 which is 8 start up frames and a low, among other things. At the same time, Flash's LC prevents AM from using FTD from anywhere except full screen so we have to constantly be up close and I have to manage to be in that space that I'm capable of punishing a whiffed B2, B1, D1 or a dash in so I'm basically respecting what he does more than him respecting what I'm doing. I have to react to him and "play his game" in that situation but just because I have to "play his game" it doesn't mean it's a losing MU. The second I get something started, he's playing my game and I can always take risks in the neutral game because the payoff is well worth the risk.
That's just some of my thoughts on one MU, I'm not gonna go into detail on every MU cause it seems to be quite pointless. If people want to believe Flash has losing MUs, they should at least respect the fact that the top reps think he has none and therefore, those MUs need to be actually played out offline instead of just theory fighting.
As of right now, I think it's fair to say Flash is a definite top 10 character regardless, and a definite top 5 character if he has no bad MUs. Even if he does have some bad MUs, he STILL would be in top 5 contention when you compare his losing MUs to the amount of losing MUs of Bane, SM, Sinestro, WW etc.