If it came with absolutely no downsides, of course it would be awesome if a subway could identify and charge you just by walking in. Or an Uber. Or a grocery store. It’s the perverse abuses of such technology by the government or advertising companies that makes it dystopian.

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.

Indeed, convenience at all costs is a curse that's driving towards 1984. The destination of this absurdity is why even bother thinking if someone else can do it for you...