Earlier quoted context omitted.
I keep thinking that this could be solved by just building Electron into the OS as a shared framework so we don't have to have a separate copy for every app, but the more I dig into it, the more I realize I'm just reinventing the web browser.
You are describing PWAs, but they'll never have the same API access & permissions as a native app.
There are two obvious answers. The first is portability. And sure, but Electron provides an answer here, so why can’t we provide one with PWAs? We could even have OSes define this interface for different browsers to target in a standardized way. Yes, you need platform specific code, but that’s often the situation with Electron too.
The other answer is security. But how is Electron / any other installed app any better? Because we require more explicit consent before installing a “real” app than for installing a PWA? OK so, just let’s just do that for PWAs too.