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.