They're doing a great job, ads are so addictive I've even turned off my Ad blocker so I can get more of them! Won't someone save me!
Ads would always exist, but think about how many great (even lifesaving) solutions we're missing out on because market decided they aren't worthy of pursuit.
"Nobody is addicted to ads" is true if you think only about the pop-ups and couple-second videos as "ads" - but the concept of advertisements is much wider than that. Some adverisements may not even be presented as such - they may be presented as "useful content", but which is chosen above other such useful content by the virtue of being paid for to the advertising company.
I recently turned off tracking, and suddenly started getting served ads for 'green cremation'. I guess statistically few people are interested in that, but conversions are lucrative, although the 99% of users who don't want to see it probably get mildly annoyed.
Liquidity and price discovery are useful things. Nobody would pay them otherwise.
Is there any other evidence of their usefulness beyond "people pay for it"?
"People pay for [that]" because it's a genuinely useful property of an investment vehicle.
Market economy got us into the situation where the most brilliant minds in the world are researching best ways to make internet advertisements as addictive as they can be.
Very cool innovation, indeed. Ever read The Space Merchants?