Why haven't local-first apps become popular?

Those technical problems are largely a result of trying to shoehorn collaboration onto older local-only PC era apps that store data in the form of simple files. For really rich collaboration you want something designed for it from the ground up, and Office is not. Office pre-dates even the Internet.

That has nothing to do with where the code lives and runs. There are unique technical challenges to doing it all at the edge, but there are already known solutions to these. If there was money in it, you'd have a lot of local first and decentralized apps. As I said, these technical challenges are not harder than, say, scaling a cloud app to millions of concurrent users. In some cases they're the same. Behind the scenes in the cloud you have all kinds of data sync and consistency enforcement systems that algorithmically resemble what you need for consistent fluid interaction peer to peer.

I try to use those as much as possible. We ended up in this situation mostly because of the Google push to make everything an "web-app" with web-technologies instead of protocols...

Anyone uses IMAP email? Works just fine (save for IMAP design but that's another story).

Same with CalDAV.

For stydy I use Anki and it has brilliant sync (it can even automatically/automagaically merge study changes when I study some items on mobile and others on desktop).

Many seem to claim that it's impossible to sync correctly in "colaborative environment" as in it would always involved dozens of people constantly working and editing the document (which would be utterly difficult to track the evolution of)… Most of the time it's not that colaborative and having the data locally makes it easier to work with.

OTOH not everything has to be (web-)app…

Personally I think PWAs are a bit confusing for consumers as they think "It's a website, i won't be able to use it offline." and if they get reminded that they can use it offline they usually forget.

Server-centric computing is just more efficient, and it usually becomes less popular only at because means of communication aren't up to the task at the moment.

1. In the beginning, there were mainframes and terminals. You saved resources by running apps on a server and connecting to them with cheap terminals

2. Then, PCs happened. You could run reasonably complex programs on them, but communication capabilities were very limited: dialup modem connections or worse

3. Then, internet happened, and remote web apps overtook local apps in many areas (most of those that survived required massive usage of graphics, like games, which is difficult even with modern internet)

4. Then, smartphones happened. At the time of their appearance they didn't have ubiquitous network coverage, so many first apps for these platforms where local. This is eroding too, as communication coverage improves.

So if you look at this, it is clear that main share of computing oscillated back and forth between server and local, moving to local only when communication capabilities do not permit remote running, and once comms catch up, the task of running apps moves back to servers.

> nowadays you want to have information from other computers.

Do I? What sort of information ...

> shared calendars

OK yes that would be a valid use, I can imagine some stressed executive with no signal in a tunnel wanting to change some planned event, but also to have the change superceded by an edit somebody else makes a few minutes later.

> the weather

But I don't usually edit the weather forecast.

> a social media entry

So ... OK ... because it's important that my selfie taken in a wilderness gets the timestamp of when I offline-pretend-posted it, instead of when I'm actually online and can see replies? Why is that? Or is the idea that I should reply to people offline while pretending that they can see, and then much later when my comments actually arrive they're backdated as if they'd been there all along?