Not only you are paying extra for tips and whatever the restaurant adds additional chargers to cover “employee costs” (yes this is real in the US), you are giving them more money when you put your email address in their payment system. I noticed such a trend when I started receiving advertisements from places I had visited long time ago. So this idea of saving the environment by cutting down on printed paper means more money to companies.
First they add hidden fees, now they use your email for marketing all under the guise of going paperless. Feels less like saving the environment and more like squeezing the customer. How ever few restaurants which we serves as a technology partner we made an interface to unsubscribe so it will be convenient for people like you to not getting unwanted emails