Timings and audio handling sound like logic things and not something Rust's advantages over C++ would inherently support better. If I had to hazard a guess, it

Timings and audio handling sound like logic things and not something Rust's advantages over C++ would inherently support better. If I had to hazard a guess, it's that the C++ projects are just more mature and have seen more "in-the-wild combat" to get to the state they're in now. Other factors that may contribute (in no particular order): - existing emulators are Good Enough and polishing a new one is less "urgent" than other problems in the current zeitgeist; - hobby project vs. no-longer-a-hobby project status; and - emulator projects in C++ are of similar quality are just as prevalent, but are significantly older and instead of being discoverable on GitHub are abandoned on Sourceforge or personal websites.