Windows 11 minimum supported target is x86-64-v2?
But I wouldn't mix target-cpu with os, as there should be a clear distinction, even though you could argue that Windows 11 base-line creates a new x86-64 target milestone.
Anyway we rely on the operating system, not allowing to run on unsupported processors. And that's why Rust can't use features safely which aren't in the minimal requirements of the operating system it's running on.
Setting target-cpu/target-feature doesn't solve the more fundamental problem, that nothing prevents you from running the application on an unsupported target.