16 core CPU, 64GB RAM, and 100GB of storage is definitely not a budget build, but I don't really see how that would be a "pretty insane workstation", either. That's firmly in consumer space these days and has been for a few years.
But that's also not a requirement, either, that's just what it took for a 40 minute clean build time.
I'd argue that it's not the 'default' workstation most developers who do not have specific requirements will be running, especially on the RAM side.
My personal machine is very mid-spec'ed because my personal projects are all small and don't really require much.
Even my work machine tops out at 32Gb RAM which has always been plenty, even for our comparatively large codebases (although more is always welcome :)).
RAM is cheap and easily upgraded after the fact, though. Going from 32gb to 64gb is $100
I certainly wouldn't spend that for a one-off patch to an open source project, but if you're doing this regularly it's not exactly a steep upgrade either
But that's also not a requirement, either, that's just what it took for a 40 minute clean build time.