Even the number of developers who compile an operating system on any regular basis is extremely small. For me, developing software is much less resource intensive than a light web browsing session.

I compile operating systems on a 2010 ThinkPad.

It's not fantastic for today's standards, but it's not terrible either.

I compiled operating systems (linux) on my clunky 486/100 MHz laptop 19 years ago. Ditto.