On the flip side, people have finite amounts of time and money. People want information, entertainment, etc. People are reluctant to pay for access to websites, especially since most people are paying for their Internet access in the first place.
Advertising fills in the gap, providing money to run the websites, pay for the content and the software . . . and apparently at little to no cost to relucant people unable or unwilling to pay monetarily.
The cost is there, however. It is paid in privacy, in attention, in the bits and bytes of our data caps being nibbled away, in electricity, in time . . . .
It is time to start looking for better ways.