What will win Acuña MVP this year is that he’s, now, having a better offensive season than Betts. AND Betts’ superior defense can’t realistically provide enough value to make up the difference when they play the same position, especially when it’s one of the “least” valuable defensive positions on the field, regardless of what fWAR says.
That’s the argument for Acuña to win MVP, not a bunch of meaningless stolen bases.
When Acuna plays 63 games of elite 2B you can start talking about their defense being similar.
And yes, Betts is significantly better in RF as well. Acuna has turned into a statue out there.