Few of the important things on the Web are spyvertising-supported, or wouldn't promptly be replaced by something community-driven and free if they went away or became paid-only (stackoverflow, for instance). It's mostly junk.
[EDIT] to expand, I think the piles of spyvertising money funding sites & services is a big part of the decline of truly free sites and open protocols, and make running a paid site (or app, or whatever) harder since you're competing with "free" (but spying on you). Less incentive to use them, less incentive to contribute to them. The whole system's perverse and harmful and it would 100% not be the end of the world, or the end of nice things for free/cheap, if it just disappeared tomorrow.
[EDIT] to expand, I think the piles of spyvertising money funding sites & services is a big part of the decline of truly free sites and open protocols, and make running a paid site (or app, or whatever) harder since you're competing with "free" (but spying on you). Less incentive to use them, less incentive to contribute to them. The whole system's perverse and harmful and it would 100% not be the end of the world, or the end of nice things for free/cheap, if it just disappeared tomorrow.