We've come full circle. The web developers are starting to realize there's a whole operating system underneath the browser that might actually be of some use.
As much as it's easy to shit on the web stack, it solved a real problem, namely the 'operating systems underneath' being absolute clusterfucks at least as much as the web. It's really sad that the only way to reliably access something from multiple devices and locations are websites.
Ironically, if we're ever going to see something like the OP wants, it's 100% going to be locally-run webapps. Whether we like it or not, think it's right or not, it's clear by now that the average joe is not going to learn tools like git.
It is a simple wrapper around the input devices like mouse, keyboard and touch screen and outputs the graphics using GPU shaders (DirectX, OpenGL, Metal). It feels like a mix between a 2D game engine and a UI library.
The immediate mode architecture is a mindfuck how easy it is compared to (functional) reactive programming. You basically get all the benefits of having observers of values with just values.
All this is totally fine for a game UI, and is a much harder sell for productivity software.
Dealing with something that believed it only needs a canvas to draw on is PITA.
100% will require accessibility in some form if your timeframe is long enough. We aren't young forever, you know.
Is it? Web and electron applications have the same issue, and they seem to be doing fine.
I think it's neat that folks can skip the conventional web technologies & hypertext & use the web to create arbitrary systems. But I also think this is quite a malignant & user-de-empowering & tragic development for the web. The DOM has been extremely powerful as a common language, that users can make use of directly & via extensions & scrapers. Stealing this fire back from the users, renegging on the web's promise that it's the user's agent, for them to use to navigate the web as they like: that's a great & sad regression.
In my opinion the web is worthwhile & useful. Bypassing it, treating the web like thin-client, a way to push pixels in people's face, via some auxiliary rendering process, be it local (webassembly) or remote, is a terrible usurpation of user's agency. Projects like Flutter's CanvasKit & others are a great danger to one of the few piece of technology that has enabled users some level of control & freedom, the web.
The article doesn't mention anything at the OS level. Every technology suggested runs in the browser.