I don't think we've seen that Star Wars can't support that frequency, yet. Out of the 5 films only 1 can really be considered failure. the other 4 are huge financial successes. While not a movie, The Mandalorian is has drawn a lot of praise as well.
The issue here isn't how many is coming out but rather just making good, fun, crowd pleasing movies. There also should have been, with the 3 episodes, a better, singular vision.