QEMU support exists, but needs TLC. The best it can do is "mac99" which emulates a 1st generation PowerMac G4 - it can run 9.2 - 10.5. But in my experience via UTM on a modern MacBook, it gains some Geekbench points like memory speed but loses a lot in others like integer performance.

I'm very glad that it exists but is not at a point where a powerful Ryzen or Apple Mx can compile (much) faster than real hardware.