uv has not really done that much. It's all been possible, and usually about as ergonomically. It's just opinionated in a way that people currently seem to like, and fast primarily due to good internal design (not because it's written in rocket emoji Rust sparkle emoji, although that certainly is a net positive to performance).
UV hasn't done anything except for all the parts that matter. (And while there are compelling arguments that Rust has nothing to do with it, the correlation is pretty strong)
UV has provided easy solutions for engineers that are easily frustrated by a lack of easy solutions.
There's nothing wrong with easy solutions, but any python engineer worth their salt has long since solved and moved on from the issues that UV claims to solve.
I believe UV provides value, even significant value, to lite python users, but for those working with python day in and day out, maybe you're using a new tool, but life has not changed significantly for the better. Or you just sucked and didn't reach for any of the perfectly usable solutions to all of these problems that existed before UV showed up.
uv provides a breadth of functionality that no single tool has before, and that no simple, easy combination of tools has before. For developers, it replaces poetry with something much faster and more reliable, and replaces pipenv. For end users, it replaces pipx and pyenv, and pretty much replaces pip itself (which no longer wants to be used by end users). And most importantly, uv relieves you of having to remember which of the preceding tools are suitable for which use cases.