You're right, from an evidence-based medicine perspective there is little to no proof that masks work, and some indication that they are counter-productive. There are plenty of people posting links with dozens of papers claiming to prove that they do work, but very few if any of those people seem to have actually read anything on those lists, as none of them claim what the people posting the links claim they claim. (note that I'm not claiming here people should or should not wear them, this is a position-neutral meta observation).
That said, at this point wearing/'believing in' face masks is a political issue, not an evidence based rational choice. It's tribal signaling. Noboby really knows a or b, but choosing to believe a or b has become (yet another) aspect of identity politics. Which is what worries me the most, because now that position has become entrenched, regardless of whether we reach any conclusive findings at some point in the future.