Ignoring the fragmentation of course; although that seems to be getting less and less each year (so long as you ignore Safari).
Counter-counterpoint: Maybe it's time to require professional engineer certification before a software product can be shipped in a way that can be monetized. It's to filter devs from the industry who look at browsers today and go "Yeah, this is a good universal app engine."
Maybe useful higher-level elements like layout, typography, etc. could be shared as frameworks.
There are many alternate histories where a different base application layer (app engine) could have been designed for the web (the platform)
The impact on people's time, money and on the environment are proportional.
Does it? Have you compared a web app written in a sufficiently low level language with a desktop app?
And if we're talking about simple GUI apps, you can run them in 10 megabytes or maybe even less. It's cheating a bit as the OS libraries are already loaded - but they're loaded anyway if you use the browser too, so it's not like you can shave off of that.
A desktop app may consume more, but it's heavily focused on one thing, so a photo editor don't need to bring in a whole sound subsystem and a live programming system.
It would have been great if browsers remained lightweight html/image/hyperlink displayers, and something separate emerged as an actual cross-platform API, but history is what it is.
You've reminded me of the XKCD comic about standards: https://xkcd.com/927/
Do you really want a universal app engine? If you don't have a good reason for ignoring platform guidelines (as many games do), then don't. The best applications on any platform are the ones that embrace the platform's conventions and quirks.
I get why businesses will settle for mediocre, but for personal projects why would you? Pick the platform you use and make the best application you can. If you must have cross-platform support, then decouple your UI and pick the right language and libraries for each platform (SwiftUI on Mac, GTK for Linux, etc...).
That's a terrible solution that preserves nothing. Try using a screen reader with an app rendered onto a rectangle.
Remember Livescript and early web browsers? It was almost cancelled by big tech because Java was supposed to be the cross platform system. The web and Javascript just BARELY escaped a big tech smack down. They stroked the ego of big tech by renaming to Javascript to honor Java. Licked some boots, promised a very mediocre, non threatning UI experience in the browser and big tech allowed it to exist. Then the whole world started using the web/javascript. It caught fire before big tech could extinguish. Java itself got labeled a security threat by Apple/Microsoft for threatening the walled gardens but that's another story.
You may not like browsers but they are the ONLY thing big tech can't extinguish due to ubiquity. Achieving ubiquity is not easy, not even possible for new contenders. Pray to GOD everyday and thank her for giving us the web browser as a feasible cross platform GUI.
Web browser UI available on all devices is not a failure, it's a miracle.
To top it all off, HTML/CSS/Javascript is a pretty good system. The box model of CSS is great for a cross platform design. Things need to work on a massive TV or small screen phone. The open text-based nature is great for catering to screen readers to help the visually impaired.
The latest Wizbang GPU powered UI framework probably forgot about the blind. The latest Wizbang is probably stuck in the days of absolute positioning and non-declarative layouts. And with x,y(z) coords. It may be great for the next-gen 4-D video game, but sucks for general purpose use.
