so UV and PIXI are both nice in that they provide per-project environments (though using conda envs works just fine for us), but they don't solve the actual python packaging problem in that they still depend on either the pypi or conda packages (and neither support both)
Yes. They are tools to manage the user side of packaging (i.e. installing, managing versions, locking, environments) but can't do anything to fix the problematic ecosystem. That is a much harder problem to solve.
