Star Wars' problem is their film side is a complete clusterf*** of announced projects that fall through or dates that get moved. They haven't released a movie since 2019, and that was the steaming pile of shit that was TROS. Why would anybody have any faith in a Star Wars film at this point? Streaming has at least given us Mandalorian and Andor, which are good (although I guess opinions on Mando are more split about the latest season), and Boba Fett and Obi-Wan, which while they obviously had issues, were at least entertaining or had some really great moments (who didn't fanboy out at Boba Fett riding a rancor or Obi-Wan vs Vader?).
I think Marvel's problem is more of a mediocrity problem. I think if movies like Multiverse of Madness, Love & Thunder, Wakanda Forever, Quantumania were all better there wouldn't be as much burnout. Now I do think that having so much going on might lead to some of that mediocrity. They're spreading themselves thin and maybe with less going on they can focus more on quality vs quantity.