We don't, but a model where a user pays for a service rather than being free and ad supported is significantly less likely to enact user unfriendly changes.
If the way you make money is by convincing people to pay, you are highly incentivised to make the product good, especially where there are many other free competitors who are ad supported.
Tell that to cable companies, sports broadcasts and now streaming services. The one incontrovertible fact of modern society is that ads eat everything else. No other revenue source compares.
