We actually made a great solution for this in the 90s: mailservs, inspired by Usenet. We made AOL bots that would take a file, chunk it into 1.5MB sections, and send each via email attachment. Then a client side program would download all the attachments and reassemble them. We downloaded entire movies this way. After download, the mailbox was emptied; if it wasn't, the next transfer would fail.
So people just need mailserv programs to send files, and download their mail regularly.
For example: what is storage? A router stores packets temporarily; is that storage? A DNS resolver caches records; is that storage? A browser stores cookies; is that storage? A chat or email server & client may both store messages in different states for different purposes. What storage should be shared and shouldn't be, in what specific circumstances? Who is allowed to read and write to which thing at which time in which circumstance? All of that will affect your abstraction.
It's sort of a shame that so much of the new web3 storage work intrinsically links storage to a blockchain, instead providing a blockchain integration as one of many authentication/provisioning models.
Let's think of the simplest possible implementation of that.
A todo app wants to write to 'your storage'. What are your options for storage? If it's some thing like Google Drive, that is a proprietary interface, so right off the bat, you are now implementing vendor-specific things, so an abstraction is not worth much. You could make some kind of "JavaScript Framework For Storage", aka a js library that has 50 different proprietary implementations, but that would only work for javascript apps. Which, if you only code in JavaScript, is fine, but if you want to support some other application written in another language, now somebody has to maintain those 50 different proprietary implementations in another language too. That's just not sustainable.
If instead you want to create one standard web API to access storage through, even if you could define exactly what it should do, you now need to get Google to implement that one standard web API. But why would they? They already have their own Google Drive API which works perfectly well for their own purposes. You would have to show them some significant business advantage to throwing away all the money and code they've sunk into their own API (not to mention that all their customers and their apps have sunk into it) and build and adopt this new API. (That assumes you could even get them to agree to whatever standard API you created, as they may want a half dozen extra features that have nothing to do with storage)
By modeling the whole system, you can quickly see all the weird quirky problems that you will run into trying to make this API and get it adopted. It's not impossible, but it's a much larger problem space than you imagine at first.
Tasks like this or even punters(html heading tag denial of service through instant message lol) were what got me interested in programming in middle school, no training or education, just hacking around trying to figure things out in a pirated VB3.0. The community was great with private chatrooms full of users testing and helping others, trying out tools. People shared libraries to learn from, use, adapt. Anyone remember the popular old and terribly named genocide.bas? I'd like to get my hands on some of these old proggies and code if they're still out there.. Or even just the cartoon sheep program which would run around the desktop interacting with window borders.
edit: the way I'd solve the rest is just by using a torrent magnet link. The problem with that is that you might have to teach someone how to open a port for UDP traffic, but after they've done it, sending files of any size to them becomes trivial.
With that said, better infrastructure (IPv6 + better connections) can make P2P very feasible in the future, hopefully. Or software that defaults to local connections if it's possible (so if we can find the device via a private IP, use that connection instead).
And doesn't Dropbox work for the given example? That's the mass-market productized/paid/marketed/surveilled solution.
I think GP's point is that this churn indicates that it's not a "solved problem". It's clearly solvable, but whoever runs these services doesn't find a revenue stream. It should probably be provided by your ISP just like email and usenet once were, but the cultural expectation isn't there. Maybe they get shut down because people use them for bad things? I don't know.
I think you're really just wanting some big name or trustworthy player like Dropbox to come out with a similar service. It's not going to happen--like I said by design wormhole and similar tech doesn't send or store data on any central service. There's no value for some big company to give people this service, they're literaly just burning bandwidth to shuttle invisible (to them) bits and data. They can't extract anything like advertising targeting, revenue, etc. from the service. It will always exist as some weird self-hosted thing.
Record your neice blowing off the candles at her birthday party, and the next day, her mom asks you for the original (high quality) video file, so she can create a party-video... the file is shot on a phone in 4K and uses 300MB of space.
Mail? Nope, too big. Chat platforms? Too big. Cloud upload? You have to share a link, and some services (ahem, skype) actually open those links when you send them... who knows, they might even save the files there. Also, do you really wan't personal videos in the cloud? HTTP/(S)FTP servers too much of a pain to set up for a one time need. We atleast had DCC on irc, now not even that.
So a USB flash drive it is... and a car ride.