It's also just clearly a powerful and interesting tinkering project, which there are valid arguments for, but this can just chill out on your desk as an elegant general productivity machine. What it wouldn't do that the tinkering project could do is be upgraded, act as a powerful gaming pc, or cause migraines from constant fan noise.
The custom build would work great though, and even moreso in a server room and as well continues to reveal by comparison how excessively Apple prices it's components.
The PC doesn't have to run Windows either. Strictly speaking, professional applications see MacOS support as an Apple-sanctioned detriment.
> If you've ever used git, svn, or an IDE side by side
I still reach for Windows, even though it's a dogshit OS. I would rather use WSL to write and deploy a single app, as opposed to doing my work in a Linux VM or (god forbid) writing and debugging multiple versions just to support my development runtime. If I'm going to use an ad-encumbered commercial service-slop OS, I might as well pick the one that doesn't actively block my work.
If you've ever used git, svn, or an IDE side by side on corporate Windows versus Apple I don't know why you would ever go back.