The big one is repeatability of environments. Docker is OK, but it doesn't run well on Mac, and is pretty heavy.
Also, having the processes run on the host and filesystem is great for usability.
Agreed! flox environments are purpose-built for repeatability: Nix-based, versioned-controlled, shareable with others via git. Check out the docs https://floxdev.com/docs for how to get started with environments. We have a native Mac installer as well.
We're also working on the ability to manage processes and services locally, stay tuned :)