There is plenty of consumer hardware that is supported on Linux, or will be as soon as a kernel developer gets their hands on it, reverse engineers the protocol if necessary, and adds support. For things like keyboards, there are often proprietary extensions (eg. for built-in displays, macros, etc.). It pays to check for Linux support before buying hardware though. Sometimes it’s not the kernel drivers, but supporting software (eg. Steam input) that might not support it.

First class vendor support for Linux is more common for niche/premium hardware designed in the west, than cheap chinese knockoffs that follow it. Long term customer support is not their strong suit.