Would It Work...

[Celgress]

...If Miles became the primary Spider-Man of 616 and Peter semi-retires, like what happened with Ben Reilly and Peter in the 1990s?

I think it could work. Unlike Ben at the time who was essentially a new character, Miles has been around long enough to establish himself. However, there would no doubt be an inevitable backlash. The most important question from Marvel/Disney's POV is would comic book sales of Amazing remain steady or would they fall or even collapse after such a change? That's something no one can really answer I suppose.