There was pipenv before that too, which also had a lockfile.
Funny how these things get forgotten to history. There's lots of prior art when it comes to replacing pip.
edit: here's an HN thread about pipenv, where many say the same things about it as they are about UV and Poetry before https://news.ycombinator.com/item?id=16302570
Except pipenv was never anywhere near as good. It meant well but never delivered.
Exactly I jumped onto pipenv, poetry, and pyenv as soon as I heard about them, and though they provided advantages, they all had significant flaws which prevented me being able to give full-throated endorsement as the solutions to Python environments
However, I have zero reservations about uv. I have not encountered bugs, and when features are present they are ready for complete adoption. Plus there's massive speed improvements. There is zero downside to using uv in any application where it can be used and also there are advantages.