A full guide on how to set up Steam Link on a Raspberry Pi 4 (up to 144 Hz/FPS!). While this guide was written for a Raspberry Pi 4, it should also work with a Raspberry Pi 3 and 4 with minor adjustments. That said, throughout this guide, we use an older Raspberry Pi OS called Buster Lite (10) due to stability and performance reasons from my testing in the past (runs 32-bit). However, you should be able to still follow this guide using a newer Raspberry Pi OS with some adjustments.
This is a companion discussion topic for the original entry at https://blog.moddingcommunity.com/how-to-set-up-steam-link-on-a-raspberry-pi