Ads are useful, they help you reach customers
The fact that ads are one of two types of content for which people regularly install blockers (with porn coming second) speaks volumes about how useful they really are.
"Ads are useful, they help you lie to and manipulate customers"
Information is useful, but that's not what ads are for. No one is interested in giving consumers honest and accurate information about their products without lies and attempts at manipulation. Forcing an unsolicited ad on someone is itself an act of manipulation.
Fuck that, if I need something I'll go research it. I don't need some asshole company lying to me to coerce me into giving them my money.
Even that only makes sense if endless consumption is a given good thing.
If I need something I usually have a need first, then I research then I buy. It's never the thing in the ads in between that turns out to be best.