An emulator simulates hardware with software. That’s why it’s slower than running on the original hardware, unless you’re running on a hardware significantly faster than the original.

But Wine is not an emulator because it mimics software with different software. You still run on the same hardware, that’s why wine/proton only runs on x86.

So the whole “wine is not an emulator” might sounds like pedantry but it’s not. It’s an important distinction. Because it’s not an emulator there is no inherent perf cost.