There are tons of alternative single-board-computers available. The Orange Pi 5 is great for MUCH higher end performance but still under (usd)$100, and there are other options (Orange Pi 3? Banana Pi? Radxa RockPi?) that still match or beat the Raspberry Pi 4 performance for the same recommended retail price, but new stock is available for the sticker price.
Raspberry Pi OS is pretty much Debian with Broadcom drivers they haven't up-streamed yet. It runs on other SBCs, or there's Armbian, Arch for ARM, RebornOS, et cetera et cetera, all packaged for ARM uboot SBCs.
Raspberry Pi OS is pretty much Debian with Broadcom drivers they haven't up-streamed yet. It runs on other SBCs, or there's Armbian, Arch for ARM, RebornOS, et cetera et cetera, all packaged for ARM uboot SBCs.