You make some good points. It's a bit meaningless to discuss sales numbers without actually having the numbers (as opposed to what people claim). I'm told that Rogue One merchandise didn't move as well as TFA; not that companies didn't produce enough of it. There just wasn't the same demand.
Obviously, I have a bias here, same as everyone who engages in this conversation (I remember being on the other side of this a way back). However, I think we should dispel this 'objectively ST merchandise does not sell' attitude though, because it lacks nuance and also isn't always true. It's used more as a stick to beat the ST films with, since if stuff from it doesn't sell then it means the films or characters or writing were objectively bad I guess? Maybe the current scarcity helps, but what little we do see these days does sell, take for example the Black Series Rey lightsabre or one of those Funko things. And again, there was a point where PT product was in the same place, with people making all the same arguments you're making.
Anyhow, I quoted the above piece because I found it curious and a bit revisionist. The PT really did damage the brand for many years, maybe that's a concept that's hard to fathom now. It hasn't necessarily been 'rehabilitated' either; most likely there's just fewer people being vocal about it on the internet or simply less angry generally. Also, quite honestly, this many years later still posting about how the Emperor or Yoda were ruined is just a bit sad and a waste of time! Finally, just personally speaking I think it's ironic that we're talking about the 20th anniversary of a movie which killed the franchise for a generation and the 10th anniversary for a movie that brought in a whole new generation.