This is a big one for me. But I think there is a missing level here. Local as in area, not just local to the machine.
Municipal and Neighborhood level networks would solve a lot of problems inherent in the broader internet, as well as making solving problems as discussed by the OP easier.
For example, it's a lot easier to trust your neighbor than someone on the internet (and better too). For one you can look them in the eyes and shake their hand, for another you are both governed by the same court (though this does make privacy more locally relevant). On the flip-side this means local people don't necessarily have to be great at the internet themselves to use these complex hosted programs. It's just another website rather than setting up a google docs server or using a git repo.
Continuing, another problem it solves is local discoverability. There are a thousand products out there that do local services, from craigslist, on down to "local wikis". But these services don't often care about your community, and it can be hard to know what other people are using (separating local efforts across a global network). Putting them all on a local network, with a local index (and search engines) allows better discoverability nearby (especially if portals into neighboring communities can be connected, eventually perhaps into a federation of sorts), but also services that are oriented to local needs (and issues and regulation).
I'm not saying this would replace the internet. Obviously not. But it would provide a better, safer, and more useful "local layer" of the internet to go to first (to say nothing of the social media security and child safety aspects). That also happened to be faster and more resilient (doesn't go down when the internet does). The problem of course is shit ISPs, though this is why the MeshNet people do what they do. And having applications and a community ready for it. The technology (and culture) would also be useful for communities that can't participate in the global network, from isolated communities (either due to poverty, authoritarinism, or remoteness) to future ones (spaceships, remote colonies).
Just a thought.