People who deeply care about this typically use a distro which has a strong stance on FLOSS software like Debian or Fedora
Arch Linux is more free on this as long as the user gets a more conveniant way to install everything (even proprietary software)
the Arch Linux way however is also reading every PKGBUILD (where the license is stated) before installing and if you need to have an easier way to search through licenses just programatically solve this yourself i.e. by using https://github.com/archlinux/aur and going through all branches with a script
sorry that was a blunder on my part, I wanted to say “Debian and Fedora” but autocorrect gotten a hold on me it seems