Why does that make a difference?

If it's a signed response, at some point there's another piece of code that checks that the signature is valid and returns a yes/no.

I think the reason Apple's sensor was mentioned in this instance was due to how Apple handled storage and usage of biometrics as described in here https://www.apple.com/business/docs/iOS_Security_Guide.pdf

Compare that to, say, other laptop vendors: https://support.lenovo.com/us/en/product_security/len-15999