TL;DR
I booted Debian Linux on a 4-bit intel microprocessor from 1971 - the first microprocessor in the world - the 4004. It is not fast, but it is a real Linux kernel with a Debian rootfs on a real board whose only CPU is a real intel 4004 from the 1970s. The video is sped up at variable rates to demonstrate this without boring you. The clock and calendar in the video are accurate. A constant-rate video is linked below.
This is the whole idea behind Turing-completeness, isn’t it? Any Turing-complete architecture can simulate any other.
Reminds me of https://xkcd.com/505/
Any time I see an article about someone doing things with Redstone circuits, I think about that comic.