But where is the fun then? You can easily build rather fancy CPUs on an FPGA, fancy enough to boot a small Linux system in the end.

I already had that fun back in the 80s. Wirewrapped a lot of my own projects. Now I prefer to just use an FPGA.

Good for you? Not all of us were alive then and its still a worthwhile learning activity to do at least once and its okay to be excited about it and share. After all, someone had done it long before the 80s as well.

okay then what's the advantage of my4th over something like picorv32 for you

Tiny tapeout - 2 weeks until the next one closes, plenty of time

Whaddabout https://excamera.com/sphinx/article-j1a-swapforth.html

https://github.com/howerj/forth-cpu

https://github.com/topics/j1-cpu

https://github.com/topics/forth-cpu

and countless others all over the net?