>Because its easier. Because it fits together nicer and more consistently. Also because UV is well written and written in rust so all the parts are fast. You can recreate a venv from scratch for every run.

This is the biggest thing I try to push back on whenever uv comes up. There is good evidence that "written in Rust" has quite little to do with the performance, at least when it comes to creating a venv.

On my 10-year-old machine, creating a venv directly with the standard library venv module takes about 0.05 seconds. What takes 3.2 more seconds on top of that is bootstrapping Pip into it.

Which is strange, in that using Pip to install Pip into an empty venv only takes about 1.7 seconds.

Which is still strange, in that using Pip's internal package-installation logic (which one of the devs factored out as a separate project) to unpack and copy the files to the right places, make the script wrappers etc. takes only about 0.2 seconds, and pre-compiling the Python code to .pyc with the standard library `compileall` module takes only about 0.9 seconds more.

The bottleneck for `compileall`, as far as I can tell, is still the actual bytecode compilation - which is implemented in C. I don't know if uv implemented its own bytecode compilation or just skips it, but it's not going to beat that.

Of course, well thought-out caching would mean it can just copy the .pyc files (or hard-link etc.) from cache when repeatedly using a package in multiple environments.