

You can absolutely use Linux without any GNU software. I use Chimera Linux for example (no Glibc, no GCC, no GNU utils). I even get away from some software that Red Hat created according to your definition like SystemD. However, even still, I know that Red Hat is responsible for much of the software I run since I use software like X, Wayland, Mesa, Podman, KVM, PulseAudio, and PipeWire.
It is VERY hard to run a Linux system without using code contributed by Red Hat.
No, Red Hat did not “create” glibc, GCC, or GNOME. They just contributed tens of thousands of lines of code to them. Perhaps more than anybody else over the last 20 years. Ever heard of Ulrich Drepper?
Actually, it is impossible to use Linux without using code contributed by Red Hat as they have been one of the biggest contributors to the Linux kernel itself for multiple decades now.
And to clarify, the Linux kernel is absolutely NOT a GNU project. Very few packages in a typical Linux distro are actually. The full list of GNU packages is here:
https://www.gnu.org/software/software.en.html#allgnupkgs
Compare it with this list:
https://www.redhat.com/en/about/open-source-program-office/contributions
GNU has been influential but is not essential as you can create a complete Linux distribution without any of it (again see Chimera Linux). Code contributed by Red Hat however is totally unavoidable and completely essential. It is not possible to run a Linux system without it. All the distributions you listed heavily rely on code contributed by Red Hat.
To say otherwise is not just misleading. It is wrong.
I do not use any Red Hat distributions. I do benefit from their contributions and am thankful for them.
Debian?