I used to like services that were ad supported because they allowed me to be frugal and engage without the hassle of digging my credit card out of my pocket.

But ads have gotten so much worse. (Even without considering the tracking implications.) So intrusive and heavy sometimes that I can't even access the content I'm trying to engage with. (And paywalls are just advertisements for the site hosting the content, only with more difficult requirements to get past.) And many streaming services and such have both ads and payments now-a-days.

That said, even before ads got "bad", I wouldn't agree with you, OP. It's my computer/smartphone/raspberry pi/gaming console/etc. That I bought with my own money. I should have the right to determine how it acts, just like I should be free to drive my car to the locations I want to visit and not the ones my car's manufacturer or repairer or whoever wants me to go to. I should also be free to modify my car as I wish (within the constraints that I don't do so in ways that make it a societal problem.) Were it technically feasible and I wanted to add a feature to my car that made the windshield block out all billboards (again, if it didn't cause problems like also blocking out things I as a driver need to be able to ensure I don't hit), well, I bought the car. It's mine. I should be able to do that if I like.

(And yes, that means I'm also not a fan of, for instance, the DMCA anti-circumvention provisions.)

So, if I want to modify the browser on my computer to display not the page the server sends me but an altered version with a different backgrount color or rearranged interface or no ads, it seems pretty bullshit to say that's not something I should be able to do.

The website is free to discontinue its website and switch exclusively to a print/magazine format such that ads can't be cut out without being viewed. (Though, if I were to build a machine that goes through a magazine and blacks out ads without me having to look at the magazine, they are free to switch to a model were you can only view their content on a medium they physically posess and own on their premises with an agreement that you won't modify the medium. There's no way I (nor I imagine any significant number of people) would go for... unless it was a museum or something. But the New York Times or whatever couldn't make that work as a business model, surely.) And if they can't do that and still be solvent, it's not my job to prop up their unworkable business model.

(I suppose this could lead to sites doing more to blend the ads into the content. Ad placements in the show or the ad is part of the content of the article you're reading. Which honestly is better in some ways than paywalls and annoying flashing bullshit on top of the content. And it's not like they aren't doing that already, nor like they'd stop if tomorrow everybody woke up and decided not to use ad blockers any more.)

But also, I have to admit I'm pretty much pro-shoplifting too. Not saying I've ever done it. (I almost got caught and chickened out and gave up trying to shoplift some toys once when I was like 8. Lol. Never shoplifted since.) But if I ever see someone shoplifting, no I fucking didn't. They're getting a thumbsup, a smile, a head nod, and maybe an offer to pay for what they're trying to take if I can do it without raising suspicion from the rent-a-pigs watching the cameras.

Anyway, I'd say this definitely qualifies as an unpopular opinion and you have my upvote.

Though, I'd be interested to know whether you, OP, personally have any reason to hold this opinion. Do you produce ad-supported content or benefit from ad revenue in any way?