If there's not enough consumer demand for a service, and it's not a public utility that's worth funding through taxpayer money to maintain equal access for everyone, the logical, supply-and-demand-based, hundred year-old solution is to just admit it's not a good business idea and move on.
If their leadership teams can't come up with an offering worth paying for, well, tough luck, the list of neat ideas that just didn't atract enough customers is perpetually open.
All of these currently exist without advertising. The problem is advertising sucks all of the oxygen out of the room, convincing you it's the only business model because it's so lucrative.
Look around at the businesses that are entirely supported by advertising and ask yourself honestly how worse off we would be if they disappeared overnight. Do you believe that the vacuum they left would never be filled by other business models? Sure, it would probably look a lot different, but that's the point. What we have now is horrible, and I don't think society collapses if we got rid of advertising.
- Governments and companies are in symbiosis. Companies can influence which laws are passed and how they apply to them, and governments depend on these companies both financially, and practically for their services. Nowhere is this clearer than in the US, where actual CEOs are now running the country.
- The general public doesn't really care about these issues. For most people their data and privacy isn't a concern, and even when it is, it's not a large enough of a concern that they would be willing to stop using these services, or use alternatives. Since advertising/propaganda works on a subconscious level, they're literally brainwashed to not see a problem at all.
So I realistically don't see a way out of this. It would require changes in deeply rooted sociopolitical systems just to get on the right path, and then years of effort to keep us there. And without unanimous public support for all of this, it will never come to pass.
As for alternative business models, that's the least of our problems. Technical solutions for this exist today, and wouldn't be difficult to expand and build upon, but the actual challenge is changing the public perception of what "free" means. The solution likely wouldn't be as profitable for companies as advertising currently is, which is why we would need regulations to force it. When weighing the success of another billion-dollar corporation against our society's mental health and stability, the choice is obvious to me.
Regardless, I block all of their ads anyway.
How will one fund the server costs for newspapers, social networks and search engines?
Note that lots of people won't (or mostly can't) pay, so how does a social network work in this case?