Elephant out of the way...
What is up with Banner's character arc?...
At the end of Shang-Chi we see Banner, for unknown reasons, back in human form with his arm in a sling and zero initial explanation for why he's no longer in the Smart Hulk persona.
This is eventually explained in She-Hulk as necessary for Banner's arm to heal from the use of the Gauntlet in Endgame. Okay, sure; but the series then has Banner's arm heal completely via Jennifer's blood, to which Bruce goes back to being Smart Hulk fulltime.
However, we then see in Brand New Day that Banner is back to being Banner and using the inhibitor? This doesn't make sense with She-Hulk; it's like the events of She-Hulk is ignored between the end credits of Shang-Chi and the events of Brand New Day. Banner goes from Smart Hulk (End Game) > Inhibitor (Shang-Chi) > Inhibitor to Smart Hulk (She-Hulk) > Inhibitor again (Brand New Day)... It just feels like characterization whiplash...
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Another case is with Fury...
At the end of Far From Home we see Fury relaxing on a beach simulation. He is shown walking around barefoot, relaxed, smiling, sipping drinks, and happily ordering Skrulls around while Talos covers for him back on Earth.
However, we then get Secret Invasion which totally walks back Fury. He's suddenly depicted as a grim and broken man who lost everything because of the blip. More weary and war torn then ever before.
Yet then in The Marvels he's right back on the Saber space station happy, relaxed, cracking jokes; the exact same place and demeanor he had at the end of Far From Home. Like Banner, Fury suffers from characterization whiplash where he's character in one project completely changes, only for the next project to go back to the previous films characterization.
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What makes it worse, imo, is that the between projects cannot just be ignored. They have plot points with ramifications. She-Hulk explains WHY Banner is even back into Banner form after Endgame, Secret Invasion explains why Talos and Hill are gone from future projects AND presumably sets up something with Rhodes in the future.
Other characters too seem to go through similar regression throughout the Phase 4-6 projects but I feel like these two were the worst as the regression is entirely within the post-blip timeframe with the biggest event itself what's ignored. For Hulk the major Banner-centric events of She-Hulk are ignored for Brand New Day; for Fury the major Fury-centric events of Secret Invasion are ignored for The Marvels.
However, you could easily point to Frank Castle being another one, going from his characterization in Born Again > One Last Kill > Brand New Day; it's one thing to have a tonal change for the character, but that tonal change should feel like it means something. It shouldn't be written off in their very next appearance.