On Fedora you could do flatpak list --app to look whether Steam is installed as a flatpak. If not it's installed through dnf, but that can be tested by running dnf list installed | grep -i steam. You could also open Fedora Software and I believe in the top right is a button to select where a package should come from. There'd be the option to choose between flatpak or rpm. Another way to test is to open a terminal and type in steam. If Steam opens, it's a rpm, if the command is not available, it's a flatpak (you'd need to use flatpak run com.valvesoftware.Steam, iirc).

Packaging software is usually not that difficult, especially if it's already packaged in another packaging format. E.g. .deb and .rpm put the same files in similar places, the difference is mainly how It's specified where a file goes. Because Snap and flatpak are providing a sandbox, complex software like Steam can behaves unexpectedly (fixed a few years ago for flatpak).

tl;dr

You're right, it's not worth the effort. Both rpm and flatpak should work flawlessly. If multiple games actually have issues running trying out a different package might help, but I didn't have issues for many years, so you probably won't either.