I'm not convinced that Unicode fixed anything. I was kind of hoping, way back when, that everyone would adopt ASCII, as a step to a more united world. But things seem to have got more differentiated, and made things much more difficult.
The options were never ASCII or unicode though. Before unicode we had ASCII + lots of different incompatible encodings that relied on metadata to be properly rendered. That's what unicode fixed
Besides I like being able to put things like →, €, ∞ or ∆ into text. With ascii a lot of things that are nowadays trivial would need markup languages
