uv has a lot of great features, but the dependency resolution is why I'm a fanboy. It can resolve trees that pip gives up on, and it does it 20x faster than poetry (100x faster than pip) - saves me half an hour on some big projects. All the python resolution and environment management and stuff is just gravy.
I've only seen pip give up twice and both times were due to bugs that were actively being worked on and the project dependencies were quite old. Perhaps that's why I am less impressed. Don't get me wrong, working faster without any downside is great. But I don't change dependencies all that often for it to matter if it does it in 5 seconds or 30.
Yeah, this is when it really matters that they wrote it in a CPU-performant language. There have been times I pointed uv at a random pip-managed GitHub project to rescue it because the author forgot to specify some versions and entire deps in requirements.txt. It even took uv a bit of chugging to find an overlap. Also wow, those packages had a lot of pointless breaking changes.