Adding to this.

x86 Most random Linuix ISOs will boot on anything. I've seen software compiled before the hardware had finished being designed boot just fine. (in the latest case lstopo was very confused, but everything still worked!)

ARM, I go looking for a build for my chip/device in particular.

x86 I just buy hardware and it works, ARM I check for OS builds before buying, and wonder if the builds will continue to get updates.....