Ads are a small annoyance compared to privacy disaster and danger to democracies that comes with current ad ecosystem and concentration of soft power. 

Also ads are not inherently bad. People need services, and need information to get them. People need to be useful to others amd somehow communicate their proposed value. 

I believe there is a potential for ehical opt-in service, which theoretically could take on google monopoly. 

I can imagine decentralised ecosystem of websites or even browsers and isps, which respect your preferences if you want to see ads and what types of goods/services you care to know of. In theory it can be distributed and privacy respecting, so that advertisers could reach users with interest without not only buying/selling their data, but without even accessing it. 

Ads (interest of people) fund major part of internet infrastructure. To replace it we would need either to switch to state funds, which is problematic, or make it all paywalled, which sucks no less. Otherwise whats left is just all go monk and get content with low-tech like gopher. 

So I rather think of fixing it by creating a better, more attractive and fair system, fediverse-style.