I love looking back 10+ years for the cheapest Linux thing you could buy. People were buying devices that were for kids or a router or something and repurposing it because it was open enough to get a shell on / flash Linux to it and start doing projects with.

In the 2020s or somewhere before that we got a bunch of dedicated cheap MCUs that were good enough and I think stole the thunder from full Linux but there are still projects to run it on things like the ESP32 family.

Either way, hardware hacking is still my favorite hobby to watch.