Whether it is or not is not as important a question as "Can you". The answer is currently no. SteamOS is currently exclusive to the SteamDeck. Valve has no plans to port it to general PCs or other PC-like hardware.
I looked into that. It's not as seamless as it appears. I also tried Nobara and Bazzite(
https://bazzite.gg/). Bazzite was the best one for being a solid portable "gaming" Linux distro. However none have really hit the mark any better than the mainstream Linux distros. Bazzite is currently the best one I've found, but YMMV. Requires a Radeon GPU of recent vintage(RDNA+) to work right, so fair warning.
Valve should really consider making a general SteamOS distro that slipstreams all of the good things about the deck version into a general desktop distro. It would be an involved but likely not difficult effort.