[obelisk_]

Homebrew installs software into /usr/local last time I checked so unless you are doing something really strange like manually overwriting system files, you'll be hard pressed to fuck up the whole system. Personally I'd install homebrew into /opt/homebrew.

[DasIch]

The real advantage of pyenv is being able to install all interpreters in all versions. If you're developing libraries, you're going to need that.