One of the issues with the Mary Sue argument is that many who subscribe to it now look anywhere they can find and contort everything Rey does as evidence to back it up the theory. It hurts the argument to do such acrobatics (just as it hurts the argument to use the term in the first place, as that strikes up a whole different debate).
It’s one thing to say that Rey learns the force too quickly, respective of previous canon portrayals, or that the stakes for her emotional journey are too low going forward. But to nitpick and turn everything Rey does into proof that she is better than someone else is disregarding the actual filmmaking decisions and how things actually play out on screen (not to mention in some cases these arguments involve ignoring, forgetting, or fabricating things that happen in certain scenes).
My point being, I’m sorry I get flippant some times but it can be very frustrating when I want to have a discussion and it feels like when we can’t even agree on the reality of the film we’ve all seen (probably multiple times). It makes it very hard to debate!