I agree that Approval Voting seems better in almost every respect to RCV/IRV, and (therefore) much better than FPTP. For that reason I would encourage more states to experiment with Approval Voting so we can gather some more data about what sort of results and UX it produces in practice.

The reason I mention UX, though, is that I think there is one respect in which Approval might be lacking, namely how voters interpret the instruction of "vote for whichever candidates you find acceptable". Have you ever stopped to think what "acceptable" means in that sentence? More importantly, have you asked a wide range of different people what they think it means, to check they all interpret it the same way?

That's a rhetorical question, but my point is that some people (based on their personality, or the advice from their party, or misinformation that they are exposed to) might think that "acceptable" means "I can tolerate this candidate winning, because they're not quite as bad as the worst outcome", while other people might interpret it as "this candidate is practically as good as my first choice candidate (but I don't like his haircut as much)".

This is somewhat similar to the "disenfranchisement" issue I mentioned above, where some voters are able to cast a more-powerful ballot by carefully calibrating the threshold at which they "approve" of a candidate. There's also the potential for people regretting the reform, if they discover that, for example, millions of anxious Democrats "approved" of DeSantis out of fear that Trump might win, when actually Bernie could have won if they had just stayed loyal and believed in Bernie's chances of success.