> either way you're depriving the creator of revenue.

That may be the case -- but doesn't mean you're stealing. It may mean the creator might want to find a better way of monetizing, though.

> probably something about the fact that since it can be copied for free then it's not worth anything?

Not at all. The ease of duplication has no relevance to the value of a thing.

My argument is simple. It's my machine, and I get to say what bits do and do not get processed.

I should also point out that I don't block YouTube ads, personally. I pay for YouTube Premium instead. I like to reimburse the creators.

However, at least outside of YouTube, advertising is a scummy, spying business. I don't block ads there, either, but I absolutely do block JS and other means of tracking me. That has the side-effect of blocking ads, but if an ad isn't spying, I'll see it. It's telling how few don't, though.