Yeah, the Majors drama aside, they failed to make audiences care about Kang as an incoming threat. Nobody cared about Kang. BUT I think if they really wanted to they could have fixed it. Recast him and start making Kang a presence in films leading up to Kang Dynasty.
But the planning in the MCU these days has just been non existant. It still baffles me how the Marvel brainstrust since Endgame hasn't been able to weave these films and tv shows together in a coherent way to interconnect them and build an overarching narrative. Like how do you not connect Loki season 1, No Way Home and Multiverse of Madness?! There should have been a direct lineage between those three projects. There should have been lineage between all of the phase 4 and 5 projects.
There was interconnectivity in that they all featured the multiverse, in the same way the phase 1 and 2 movies had multiple films that featured infinity stones (sometimes retconned after-the-fact to be infinity stones) without being direct sequels to one another
If they had been
too connected, you'd have had people b****ing that they had to watch Loki to understand the other two films, as people did about having to watch Wandavision for DS3 and The Marvels.
What I would've done would be to put all the Phase 4 and 5 movies into two buckets: one for Endgame fallout, and one for Multiverse setup-
Endgame Fallout: Black Widow, Hawkeye, Eternals, BP2, FATWS, Secret Invasion, She-Hulk, GOTG3, Thor: L&T
Multiverse: Loki, Shang Chi, Ms. Marvel, Spider-Man, DS:MOM, Ant-Man, The Marvels
with Wandavision as the bridge between the two
Make sure that each project ties heavily to those themes, eg. more multiverse elements in The Marvels and Shang Chi
More of a bridge between the past and present in Black widow
More touching on the status of superheroes in the MCU in She-Hulk
etc
(And Moon Knight and Werewolf by Night would just set up Marvel Knights)
And lastly I would've made sure Phase 4 ended with a New Avengers movie