The biggest problem with advertising as a funding mechanism is that it creates incentives to *make the content worse*. It's no longer "what can I present that will help the user". It's "what can I present that will attract advertisers and keep the user spending time where I can further target them". There's the tracking thing, too, of course, and the scam propagation, and whatever else. As well as just the raw annoyance.
There's no incentive for anybody improve "bad ads" as long as they believe bad ads still work. Even if they *had* an incentive, it's not obvious how either the people producing the ads *or* the people serving them would actually do it. The producers are presumably already placing the ads they think are most likely to meet *their* goals. And as for the servers, they have very little leverage, because, in the end, their business is "you pay me to show the user whatever you want the user to see".
Sure, subscriptions suck. So come up with an alternative, say a truly privacy-preserving micropayment system. That's doable nowadays in a way it would *not* have been in the late 1990s... but it won't happen as long as it's possible to keep leaning on advertising. Nobody wants to be the first mover on something like that or eat the development costs alone. Advertising needs to die so that something better has space to grow.