TFA explains:

* "Graphics and sound weren’t hidden behind ‘APIs’."

* Programs were written in 8 bit assembly

* Generally, the 8 bit CPU was considered a complete package, rather than just one small piece as RV32I is.

Those sound nice to have for didactic purposes. 32 bit could do that, but the RISC-V ecosystem/community seems keener on integration with wider world, rather than keeping a small complete system.

I'll check out some 8 bit ecosystems/communities. Video game space seems active? Or maybe there's a RV32I community for writing retro style games, with some simple graphics support?