It's not that it "has to be" a one-to-one alternative.
It's that Universal had a chance to do a lot of good for the park with a single project, but they've now decided to very slowly piecemeal their way through improving USF (if that's even how they view it), and given what else is on their plate (EU, eventually returning attention to IOA because it will be that park's "turn" for new things), it's going to take a long, long time to address everything that I think needs to be addressed in USF.
Nobody else seems to feel a sense of urgency about any of that, and that's fine! But I do.
I'd feel much more confident about such a thing if Universal had said "This is just the first part of a larger reimagining of the area."