Electron is basically a framework for native apps, they're only "web" apps in architecture and language choice. They have all of the same permissions as native apps and basically zero sandboxing. They're frequently extended using low-level code. They can call out to system libraries.
For the scope of the current conversation, Electron apps can already be file handlers on every single desktop platform, so we're pretty clearly not talking about Electron when we critique these new web standards. Electron doesn't care about your opinion of web standards or what is or isn't getting fast-tracked in Chrome, Electron can already do whatever it wants.
That's not to say that Electron's lack of sandboxing isn't a problem, it absolutely is. But it's just not really relevant to what we're talking about right now, and it's a problem that almost every native app platform shares with Electron.
One of the goals with introducing newer "riskier" standards on the web is to get an application platform that does have sandboxing -- it's to be able to use Electron and other unsandboxed apps for fewer things. Whether that's a good goal I'm not going to comment on; different people have different opinions on the direction of the web as an app platform and whether it's smart for Google to be breaking all these holes in an otherwise decent sandbox. But regardless, Electron is not the web.