The one place I thought ads were relevant was on google search. After all, I was searching for the product they are advertising.
But the line started to blur when they decided to remove that yellow background that tells me the result is an ad. Now, it's a 11px font that spells ad. That's the only indicator.
For myself, I created a single use extension that turns google ads background to yellow[1]. I'm fine with ads on Google search, as long as I know they are ads.