Unless you let that alcoholic guard two warehouses, and allow him to have a few bottles from one of them. In that case, he'd be stupid to take from the one where's he not suppose to.
I assume you are extending the analogy by implying that one "warehouse" would be paying users, and the other "warehouse" is free to use / advertising / giving up private data users.
This analogy falls flat, because unlike an alcoholic which can be satiated at some point, FAANG can never be satiated. More information is always good. Thus taking data from both warehouses is better than restricting yourself to only one.
Secondly it also falls flat because your paying users is often the more juicy targets (from an advertising point of view), since they are already well enough off to pay for ad-free internet services, thus also well enough off to target for more lucrative advertising.
Getting back to the analogy, it is like an alcoholic guards two warehouses, one stocked with free budweiser beer, and the other stocked with the finest scotch, and hoping he wont take a swig from the scotch.
Unless the alcoholic is the only employee that will do the job (zero competition), which means he can steal from both warehouses and still not get fired. Same situation with Google/Facebook/etc, they're too big to fail and can do nasty things without any consequences.
