What we need is a cross platform package manager that installs stuff in the same place and make stuff behave the same, so shell configs can be unified between OS and not have "if" all over and expect same environments.

nix is almost that, except some packages are too old but otherwise, I have it running identically on macOS and Linux.

Homebrew puts stuff in some weird location that is /home/linuxbrew/.linuxbrew/ on Linux and that alone puts me off and it breaks if I change that location. No idea why they don't just use a path like /opt/homebrew/ for both OS and be done with it.