I suspect that this sort of project requires them to develop tools that significantly lower the barrier to performing automated biometric data gathering. It is also easier for them to link your body to your digital presence and identity since you need to use your Amazon account. A store using this sort of tech could therefore much more easily monetize your biometrics.

In any case, we desperately need regulations to govern government/corporate use of individuals' biometrics.

yes. you are right. what makes a supermarket “better” is that their tech is not yet there + you can in theory pay with cash making it harder to link your identity with your characteristics.

we need strong privacy laws so that the penalties for collecting/abusing biometric data is a strong deterrent for whoever does this kind kf thing.

Yea, I'm absolutely onboard with privacy laws that make this kind of mass biometric recognition illegal or subject to very strong constraints.

The point I (poorly) tried to raise wasn't: "well, grocery stores could do this too, so it's not a problem". Rather, it was more: "shouldn't this be even more alarming, given that it can already happen at most stores across the country".