The "Steam Client" has ALWAYS ran on ARM devices (Android & Linux) however in the past it only enabled Streaming Windows games FROM OTHER devices on the same LAN that were also running the Steam Client.
I'll have to pull out my Odin2 Mini and do a refresh. While the best case is that the Steam client would automatically grab+install the needed translation layers having to surf by Github & figuring out how to get it onto my handheld is now on my 2-do list!
Valve has quietly published the first official Proton 11 beta with ARM64 and FEX emulation baked in, and the enthusiast community has wasted no time. Thanks to the Rocknix Linux distro, YouTuber ETA Prime has demoed native Steam running on three ARM-based Android handhelds, with Hollow Knight: Silksong cruising past 100 FPS on a Snapdragon 8 Gen 2.