Honestly even if the tech were magically perfect I think the maximum benefit is pretty small. Pulling out my wallet to pay for something or show my id only takes a handful of seconds and it's a routine action with minimal cognitive load. Plus it has the benefit of me knowing exactly what's happening with the transaction. I can decide on the spot to use a different card for whatever reason and I know precisely when a transaction is taking place.

I'm sure the automatic charges described here would be loved by corporations, which would try to find ever more clever ways to manipulate people into making even easier impulse buys.