The Raspberry Pi isn't the only board around. If you need something very specific then fine, but most software that runs on it, either has been already ported,

The Raspberry Pi isn't the only board around. If you need something very specific then fine, but most software that runs on it, either has been already ported, or can be easily compiled to run on many other boards. Just spent less than 5 minutes and found loads of boards that run Linux out of the box. Most of the NanoPi at friendlyarm.com are in stock, so are most of the Pine64 boards at pine64.org; many H3 based OrangePi boards are available from multiple vendors on Ebay, also many Olimex, Sinovoip, Beagleboard, etc. are in stock right now at tme.eu. In the meantime, I just swapped my Rpi4 4GB with a 1st gen used Chromebox unlocked and reflashed with LibreElec; the performance gain compared to the Rpi4 is very noticeable. I just had to purchase separately a Pulse Eight USB-HDMI-CEC interface (the Chromebox HDMI port doesn't support CEC) so that I can use the TV remote with Kodi as well.