The Conda package manager is available to users of the Anaconda/Miniconda distribution, which is very popular. Conda uses a sat solver for dependency resolution. It's a lot slower than pip, but it's not a thing that has to happen often enough for that to be a problem.

It's a good thing, however, that using conda doesn't preclude one from also using pip.

Conda indeed is slow. However, mamba is a drop in replacement for Conda and uses a way faster solver, which makes it a lot more palatable.