How do advertisers know which particular sites are "a thing", especially smaller sites that are too big to be run as a pure hobby but not yet big enough to be household names?
And you can't.
But you have to remember, we never signed a contract with teh internetz that these folk have some sort of right to existence.
The model is broken, and needs fixed. And if some sites go out of business, well - insuring their right to deliver malware is not what we signed up for.
What is needed is "ethical advertising providers" as a service. With vetted ads checked for problems. Then I might consider turning off the programs I use to protect my systems.
In the meantime, if a site won't let me in, I just look it as if I caught a 404. And there is a real problem for them. Because while they might have successfully stopped me from seeing their content - they have also not shown me their advertisements. So they have not achieved anything other than saving a second or so of bandwidth use. And if Forbes or some other ad blocker blocking site went away tomorrow, it would be a net positive thing, AFAIAC.
As well, the parts of my internet use that I have to do, is research at sites that don't provide malware. The rest of it is merely entertainment, and I'm more than willing to find other ways to entertain myself if they try to make blockers illegal. I'm not certain that's an actual win for them.