This is why I don't understand the purpose of electron apps. Why not remove the electron part and just install and run a local http server written in any language and access it from your browser? No need to download the same 50MB+ for electron every time. The overhead from running multiple browser engines is gone. Basically everything is as it should be.

The Kimchi KMV UI is a pretty good example how to do it. https://news.ycombinator.com/item?id=12477030

Well I think it has something to do with the web's success.

For one thing, the HTML/CSS/JS separation of concerns made it so that someone could make a non-interactive, static web page with very little knowledge. The basics of HTML and CSS can be taught in a week. This is important! I think we would have far less success training people to create static documents with many of the various programming language UI Kits. Though becoming less important, there was definitely a time when this helped to increase the adoption of browsers (and I would argue still makes it easier to teach).

Another thing, is the HTML/CSS/JS were all open standards that have accepted contributions from a wide range of parties. Look at scheme: beautiful, consistent, and completely unused. HTML/CSS/JS would without question be much more pleasant if they had been designed by a benevolent dictator. But open nature of the RFC process I think both greatly helped adoption as well as contributed to the inconsistent nature of the APIs.

You only have zero-install (i.e. ships with the OS) because the web got wide spread adoption, and I think HTML/CSS/JS contributed to that.