There are privacy concerns with this, of course, but DuckDuckGo and modern Safari (with cross-site tracking prevention) helps mitigate a bit of it.
What's happening today couldn't be more dramatically different. Tracking your activities around the entire Internet, then using your own computing resources to auction them off to the highest bidder for every new page you view.
I don't have a solution to the ethical conundrum. But accepting this kind of thing cannot be it.
They'll never even notice, and in the meantime you're at risk of all sorts of trackers, malware etc. Plus...you're seeing adverts all the time. I used chrome on android the other day and I couldn't believe how many there were, or how annoying. If you're not clicking on them it means nothing anyway, as far as I can tell. I remember back in the day sites saying "click on the ads - it helps us" but I don't think that's a thing any more. Perhaps I should knock up a script to visit random sites with ads and maybe click on a few, in a container/vm. Would that help?
Don't worry, there's enough publisher-side fraud already doing that for you!