With the quality of the MCU declining overall since the Infinity Saga, it would make sense to assume that some of the blame falls on the concept of the Multiverse.
Dr. Strange in the Multiverse of Madness had a lot of great things, but fell short of what it could have been, and it was all about the Multiverse. After all, Multiverse is in the title. To make things worse, Dr. Strange’s second movie came out the same year as an extremely successful, and completely unconnected movie about the Multiverse, Everything Everywhere All at Once. In addition to that example of a Multiverse movie that worked, the MCU already had its own successful Spiderman: No Way Home (Well they sort of share it with Sony, but you get the idea).
Now while Spiderman: No Way Home didn’t take us to any other universe, there were characters brought from different parts of the Multiverse, and the movie worked. There are at least a few different reasons why No Way Home worked out better than the Multiverse of Madness, but the point is, these movies show that the Multiverse concept can work, but it can’t be depended on to carry a movie.
Raising the Stakes
An argument could be made that within the Multiverse, there are no stakes. This statement is false, but the concern for it makes sense. The possibilities of the Multiverse in the MCU were first opened up at the end of the Infinity Saga when in Avengers: Endgame the Avengers traveled through time. The heroes made it a point to return the stones to their proper place and time, but Loki was able to throw things off by stealing the Space Stone and disappearing. This action created a time line out there where Loki is not around for the events of Thor: The Dark World, and it gave us a series with a character who had already died.
With Loki back in the MCU, it seems that he could end up interacting with characters who saw him die. Loki could use the technology of the TVA to find his brother, and that may seem like it negates the fact that Loki died in Avengers: Infinity War. In a way, it does, but in a way, it doesn’t. This is a different Loki than the one before. He may know what happened to the other Loki, but he didn’t live several years of the other Loki’s life. If he is reunited with Thor, it will be the same but different.
Another example that might illustrate this point a little better is that of Gamorra from 2014. In Avengers: Endgame, Loki wasn’t the only one who altered the timeline and created a new universe of sorts. When 2014 Thanos learned of the Avengers plan in Avengers: Endgame, his story was already headed on a new trajectory. He took things even further with himself and his armies when they traveled to the Avengers compound in 2023. This action created a new time line where the threat of Thanos was neutralized because he left, and once Tony snapped away Thanos and his armies, Gamorra still remained.
It may seem that Gamorra’s death in Infinity War now has no weight, but it’s simply not true. The Gamorra that now exists in the 616 timeline barely knows Star Lord, and the Gamorra that died was dating Star Lord. As shown in the first trailer of Guardians of the Galaxy Volume 3, their relationship is not going to pick up where it left off. Perhaps this concept is not appealing to every viewer, but there is something compelling about watching someone who is out of place. Gamorra has a fish out of water journey to go on, and Star Lord can be hopeful that he and the other Gamorra will have a good relationship, but he has to accept the fact that that might not happen, and even if it does, there will always be a version of Gamorra that will be gone.