Red Hat are no better or worse than Canonical at the end of the day. If you're dead set on avoiding anything with corporate backing, I guess switch to Gentoo or something.
It's centralized and controlled by Canonical, it enforces updates and you can't disable it, sometimes when you uninstall snapd it cames back when you apt update and most importantly, it is painfully slow.
That's how I started out! It was a pretty decent experience.
However, I would rate Debian as a slightly better choice over Mint. You see, Mint is a fork of Ubuntu (which is a fork of Debian). So when I needed to troubleshoot an issue, instead of just googling "Linux Mint [my issue]", I actually sometimes had to google "Ubuntu [my issue]", or even "Debian [my issue]", depending on the situation. This is because Mint and Ubuntu share large similarities with Debian, but with certain particular differences; for any given situation, I didn't necessarily know which differences played a role. This is actually why I switched to Debian; I figured, my experience was going to be basically exactly the same, just with more straightforward troubleshooting.
If you're worried about user-friendliness, then the good news is that's largely to do with your desktop environment (GNOME, KDE, Cinnamon, etc). Whichever one you pick, it will pretty much feel the exact same no matter whether the underlying distro is Debian, Ubuntu, or Mint. Especially because they're all Debian-based.