> Clearly the proper metric that used here is to charge for LTE
> data use per individual
Change service provider, or probably country
Some operators have not just "per device" but even "per family" plans. You purchase mobile subscription where the fee for data transfer can be shared between multiple devices belonging to multiple persons within family. You just pay small fee (~3$) for extra SIM cards. Limit is 4 cards.
There are also various promotions, for example during the first 6 months LTE data is free (but capped to 100GB before throttling to 2Mbit/s).
Oh, and there is no minimum lenght of subscription, so you are not tied for 12/24/36 months.
Of course majority of operators will make every attempt to milk you, and make you pay for every "service" they perceive.