The tier list, over time, has gradually shifted over from "ideal play" to "a prediction of a character's potential". It's a mixed approach that makes the Smash community one of the best at making a tier list, imo. We create a "hypothesis" using our perceptions/knowledge of characters thus far and look at the data (tournament results). If it matches up with our hypothesis, then we set it aside (e.g metaknight, ICs). If it doesn't match up with our hypothesis, either because the hypothesis seems to overestimate or underestimate the success of the character, then we look at the reasons that there could be a disparity between the hypothesis and the data. I honestly think that this interpretation of the tier list should be the predominant one because then it gives room for discussion while preserving the integrity of the BBR if it makes a wildly unpopular tier list (i.e. there's no guessing why the list is bad, either the initial hypothesis was no good or the data was believed to be insufficient).
Let's apply this interpretation to a specific character: Marth. My hypothesis for Marth is that he is among the top 8 of the game. The other seven characters would be MK, Diddy, Snake, Olimar, Ice Climbers, Falco, and Pikachu. Thinking about his tools, this isn't too unreasonable. So what does the data say? The data shows that several Marth players have had success across the span of the metagame (time and location wise). Additionally, there have been enough results (bar Pikachu) to substantiate the other characters being in the top 8 also, and Marth's results are good enough relative to theirs to have him be up there. So having Marth in top 8 isn't really a problem, and further hypotheses made about Marth should work further proceeding from this conclusion.
Let's make another hypothesis now , then, to answer this question: where does Marth fit in the top 8?). I would say Marth belongs at the bottom of these 8 characters because while he has all of the tools to win, the fact that he requires such technical play and that his risk-reward is completely skewed for deviation from practical technical perfection makes him prone to inconsistency. Meanwhile the other seven characters do not face similar difficulties and have abusable characteristics. Watching players' matches, this seems like an adequate explanation for his lower placement on the tier list despite the variety of his tools, and we move on.
So why mention all this? Well look, Dark.Pch here has a very strong hypothesis for Peach and has the frame data to show the potential. But the results data does not match up. So then we ask a few questions. Are players playing in the way the hypothesis describes? Dark.Pch doesn't think so. Evaluating the play of higher level Peach players, it appears they selectively abide by parts of the hypothesis. OK, so why have we not seen something like "the complete Peach" as Dark.Pch describes?
One possible reason is, as Dark.Pch said, a lack of motivated players for Peach period/a lack of players with the correct mindset. Even if they are motivated and have a healthy competitive mindset, Peach players do not possess sufficient knowledge of the character (i.e. the "model" created by Dark.Pch). Dark.Pch weights this strongly in his evaluation, so the hypothesis should hold despite discrepancies in the data, and soon enough there will be results to substantiate the hypothesis. He might even advocate that Peach should therefore be ranked higher on good faith.
Thinking more with respect to the character, let's ignore the fact that Peach's counterpicking game is decently limited and instead focus on technicality. If we agree that technical precision is a part of the character's potential success, then just as we did with Marth, we have to evaluate just how much technical precision affects Peach. Our answers to the different questions posed in this part of the evaluation could help support or detract from Dark.Pch's hypothesis (and subsequent counterargument against the data discrepancy).
1. Given that she has to be technically consistent, to what extent does she have to be consistent? I.e. how often? Based on the model described, the answer seems to be "most of the match".
2. What happens when Peach is technically insufficient? Most of the time, she seems to be fairly easy to punish based on the model described. These punishments result in disadvantageous positions for a variety of matchups (as opposed to a reset to neutral).
2a. When she is put in bad positions, does she have the tools to return herself to neutral? I would say that she has a hard time doing so. Trapping Peach seems decently easy to do and to continue in ledge, juggle + oki scenarios. Edgeguarding not so much due to float.
3. If Peach is sufficiently technical, just how "hard" does she hit? Based on the model described, she seems to get strong mixup. That's pretty good, but there's quite a few characters that have guaranteed damage in a lot of scenarios if they don't mess up.
In other words, Peach not only needs to be precise but also gets ****ed up for a long time when she messes up, and doesn't hit hard enough when she is set up. I think that using this as a reason to explain her lack of success allows us to successfully justify her lower tier position despite the potential truth of Dark.Pch's model. That is, just as how Marth has all the tools but is placed lower than characters with similar amounts of tools (Diddy, MK) due to poor risk/reward, so follows Peach (in addition to other characteristics I ignored for the simplicity of argument). Peach might not have the qualified players, but even the most qualified players will mess up enough to show Peach's clear flaw(s) that occur as a result of messing up.
