Beside the difference in scale, there are also different incentives. The bartender typically doesn't sell your data. They probably don't have a list of favourite drinks which they could share with others, they just have the information in their head.

As soon as that data can be collected and sold at scale, there's an incentive to collect and sell as much data as possible, without any repercussions.

Spreading rumours doesn't pay the bills, so there's no large scale incentive to spread them.