Gamblers have decided they like their odds. Gambling costs them money, and some ruin themselves that way.
If I don't click on ads and don't buy anything, it's like I'm rigging the slot machine never to pay out.
If everyone does that, then advertisers will catch on to the reality that the ads are not working, and pull out, and so then the advertising platform tanks.
So yes, you are "stealing" by not clicking on ads, and not obeying the ads just as much as if you just block the ads.
People who don't block ads, but take no consumer action in response to ads, are not in any ethically different position compared to those who actively block ads higher up the event chain.
Possibly in a worse one, since those ineffective ads are a waste of resources. It's like leaving the heating on in an empty house.
