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. I'm fine with ads on Google search, as long as I know they are ads.
It's clear Google removed the previously obvious demarcation between ads and results specifically to make it less obvious.
I'd prefer a different background colour (like the parent's extension), but it would also help a bit if it said "Advertisement" instead of "Ad".