People talk about electron being 'the only way to create cross platform apps' and ignore fltk, juce, qt, gtk, wxWidgets, tk and a whole host of other solutions, not to mention making a local webserver, opengl guis etc.
When someone only knows javascript they might want to work with electron, but no one who is going to use that software wishes it was made in electron. That's the bottom line, people don't want it, it is a selfish decision that creates terrible interactivity and grossly bloated software.
Not browsers, not photo editors, not games, not many chat applications. Certainly there must be some big ones that do right?
The dozen cross platform libraries that have been around for multiple decades are all 100 times faster than the electron, that's the point.
Obviously none of them include the Web as a platform (unless you count Java applets, which you shouldn't since they're basically dead, even if they'd seem high-performance and quite nice compared to what we've replaced them with).
If you're defining "cross platform" as, strictly, "the Web", then I'm not really sure what kind of exchange you're trying to have or what you're trying to add, here. Obviously only the web satisfies the criterion of being the web. Which makes me wonder even more why you didn't find that obvious.
"Well, no, we've had that for a long time, especially if you consider the performance compromises of Electron or in-browser 'apps' to exist within the acceptable range. Electron does make mimicking this year's UI trends as easy on the desktop as on the Web, and doing so on every platform at once, and that was hard before."
"Right, but do those earlier solutions support the web as a platform?"
"... huh?"
See why I'm confused about where you're taking this? It's like someone claimed that airplanes were the only way to travel by machine, and I pointed out that, for one thing, trains existed before that, and now you're asking me if trains can fly. No—and, again, obviously so unless we've got some seriously different life experience, here—but that's... a complete non-sequitur to the conversation already in progress.
The first thing is using web technology to build apps that are distributed as native apps on many platforms (which works because there are open source web browser engines that already support most computer platforms). This is what Electron is.
The second thing is for any cross-platform framework to support targeting the web, because the web is itself a very huge platform. This is important, because not all platforms and situations support installing native apps. If you want your cross-platform app to work on web browsers, you need your cross-platform app to support targeting the web. This might be important if you want your app to work in computer labs, for example.
Seems to me the desire for having "web" as a platform isn't so you can also support a browser application. Its so you can make it a web app and call the job done.