> the available emulators may just not be good enough, such as for example the CDi and 3DO.

funnily enough, the first public version of 3DO is now available on the MiSTer (se: https://www.youtube.com/watch?v=pyew7oHGyNE) - its doesn't seem perfect, but its not nothing!

Emulating the 3DO is a complete pain in the ass, several reasons:

1. There’s not that much interest in general, most anything interesting got ports to other systems.

2. There’s no such thing as a 3DO. There were several, and all of them function slightly differently, usually an irrelevant difference in functionality, but if you’re making an accurate emulator it means you need to make a dozen emulators, actually.

3. Apparently the hardware is just weird in general. See also the N64 for an example of a system that suffers from this.