Even if it turned out that Red Skull was just as sinister as he’s always been, there’s not really a place for that type of villainy anymore.
The Red Skull’s lip-smacking villainy is what made people like him, so without that, what are we left with?
A guy who wants to use a glowing box to make a bunch of bombs doesn’t really fit into that puzzle.
It’s important to note that comic book Red Skull is super hateful and racist, which is just depressing and I don’t think really has a place in the MCU.