I love your attitude, and I agree that we should be trying to fix this, but the problem is not a lack of signal, it's an increase in noise. Fixing the web means changing it in fundamental ways.
Suppose your webbable hobby is curating trustworthy product reviews. You're the hero that's going to fix the web AND capitalism. You can still do that, but you're going to help fewer people because you have to split your attention between you know, doing the thing, and doing the kind of marketing which helps people tell the difference between your thing and the ones that are secretly ads. Meanwhile, the bad guys can focus entirely on the latter. Sorry about the time you wanted to spend comparing blenders, your hobby is now competing with marketers... Or you have to make peace with either obscurity, or contributing to the thing you're trying to kill, because you know that the second you start making an impact somebody is going to rehost your site interleaved with misinformation.
Yes, let's fix this thing but the answer is protocols with different inherent priorities. We can't shout over the noise, we need to build something less noisy.
My personal view is that we should stop building trust around server names and implicitly trusting whatever those servers send us. In this model the non-content-generating work converges on systems to identify and remove malicious content (either from the server or from the browser screen).
Instead we should be addressing content, and sourcing it from whatever device has a copy and is most near. Our browser should know which people we trust and should make it easy for us to lean on that trust such that we can propagate only the trusted bits in the first place.
That is: stop identifying ads so that we can block them, start identifying trustworthy content so we can all participate in propagating it more efficiently and supporting it's creators.
Or to put it differently: there needs to be no way to spend money to promote content. No third parties injecting bits anywhere. If you notice that kind of shit, you apply annotations which distinguish the signal from the noise and then you propagate only the signal. If people abuse this power, you revoke trust in them and move on.
It'll require an awareness of information hygiene, which will be work to maintain, but all of the alternatives I can see involve tolerating life in a Skinner box