If you mix the two crowds: the people that actually care with the people that will just want faster apps, you get a powerful bootstrap traction.
Lets also not forget that things might just vanish and when we are able to collect them and make personal relations that make sense to us, we will want to be secure that things that matter to us wont go away because we are keeping them. Its pure psychology.
The parent poster is forgetting that before we get use of how things are right now in the digital realm, we had to deal with the material world and thats how we shaped our minds. And in that world we learn how important is to keep things nearby and have mnemonics to help our minds that needs to keep so much information that our devices become our second brains.
I'm working on a fancy chromium inspired prototype to tackle this exact issue and just with what i got here working in "prototype mode" i kind of don't want anything else.. it's just.. another level.
Its technologically superior and even ordinary, unaware people will just want this. Cloud have its place of course, but "local-first" will eat a lot of their lunch in the coming years.