The implication here is that money spent on ads is largely wasted.

Companies like Uber and Ebay have turned off all their adspend and saw little to no change in their acquisition metrics. You can argue that they were just doing it wrong. But the point is that, if even they are doing it wrong - and getting nothing in return for the millions they're spending on ads - then it's very likely most others are in the same situation.

You are right that this doesn't mean _all_ advertising is useless, there are absolutely profitable usecases. But the larger points still stands: most money being spend on advertising right now is likely not returning anything.

We now have some strong precedents being set. I believe this will cause more major companies to run the ultimate experiment: turn off all ads and see what happens. It's too early to tell, but it's not impossible we'll see adspend drop significantly across the industry once everyone finds out they're just burning money.