As I have speculated, trading X for a good, young starting pitcher and then signing Francisco Lindor in another year is a big upgrade. As others note, there may also be other star shortstops on the free agent market in a year or two when the Sox struggle up from the mat: Correa, Story, Baez...
Lindor is the prize, though, as Mr. Smiles would become the instant, new, face of the franchise -- one that will be desperate for a positive PR splash -- a Mookie replacement requiring Mookie money, albeit at a more premium position. He may be a notch below Betts in production, but also a notch above Bogie on defense.
Problem is, Lindor is also exactly what the Yankees need, as they're just not as good on D with Torres (who can move to 2nd or 3rd) instead of Didi.