You're not wrong, it's definitely not something a n00b should attempt in most cases. But I've done this before to save myself the need for distrobox. A lot of proprietary software only offers .deb, but is usually either statically linked or comes with its own set of nearly all the libraries it needs. So just extracting and running it often does the trick on non-debian distros like Fedora in my case.
Seriously though, just use distrobox or see if there's an unofficial package for your distro that you trust (AUR/copr/ppa/OBS). It's more straight forward especially if you don't know what you're doing.
You can get Steam on just about any distro, for years at this point. And there's always Flatpak for these cases too although for Steam I recommend native packages.