As stated from official Valve’s page https://www.steamdeck.com/en/oled
“Use your Deck as a PC, because it is one.” So Valve did market it as a PC and it’s one of the reasons I bought one more than a year ago. And it’s really my desktop (that I bring with me to places occasionally)c
I remember when I did the switch in 2008 and never looked back. I had a similar experience where across a few years I have been trying different distributions and finally settled on Lubuntu. Years have passed and different machines as well. Now my main driver is a Steam Deck with his Arch based OS and a secondary pure Arch on a sd card for more specific tasks.
Linux made my life more comfortable and relaxed, without even mentioning secure. My family uses Linux now, Windows is long dead.
We are free.