Don’t try to use it, it’s an old discontinued version of SteamOS based on Debian that was around long before the Steam Deck.

Bazzite will get you a similar experience to the current Steam OS with better desktop experience.

As you’ve been daily driving Linux for 7 years already, I don’t understand what issues you think you’ll have with Arch?

Worth trying Only Office and Libre Office side by side to see which one works better for your workflow.