I've been into Linux since 2006 and Linux gaming for almost just as long. When Valve announced a handheld PC with a Linux OS that actually has a ton of game support it was a day one preorder for me. I'm super happy with it. It's such a polished experience with SteamOS that it's become the main way I play games anymore. It has the benefits of a handheld console and the openness of a Linux PC. It's by far the best gaming purchase I've ever made. I picked up a ROG Ally as well to attempt to run Linux on it but the out of box experience is garbage compared to the Deck. Windows is a terrible handheld OS and Armoury Crate is a terrible user interface. The performance is better, yet everything else leaves much to be desired while the Deck is an all-around solid and refined experience.
You just have to be willing to say no to games that don't want to support Linux, but that's easy having run Linux on my desktop for years.