There has been a long standing piece of knowledge in the computer industry that if you are not the customer, you are the product being sold. That is to say that advertisers are the customer, and the data that the “free” services harvest from you is what is being sold to them.
There’s a reason why you get offers for a free hamburger if you order is from their app (and the like). If you use the app, you collect reward points and get discounts and such.
Do be very selective in what apps you install. They are all pretty much data harvesting machines.