Chrome added a file system API for some reason, but every Electron based application I've used just used the standard <input type=file> prompt and it worked absolutely fine. Even things like live screen recording and P2P VoIP can be done from the browser now.
I'm sure there are plenty of applications that need Electron, but I'm having a hard time coming up with any.
I first ran Zulip chat client in a Chrome web browser tab. But I often missed replying to new messages because I often forgot to cycle over to the Zulip tab to check for them.
After a few days of fighting that limitation, I gave up on Zulip in the web browser tab and installed the desktop version of Zulip (Electron runtime). Now new unread messages trigger a red dot on the taskbar. The desktop version is just easier to use.
If a developer has the app run locally on 127.0.0.1, they already have the capability to enumerate files (without the Web browser's cooperation).
A desktop app based on Electron-Chromium runtime has more integration options with the operating system. E.g. file system access, taskbar/Dock icon and notifications, run in the background, etc.
If a developer were to create a 100% pure web url app running locally on https://127.0.0.1/foobarapp.html -- ... they'd quickly run into browser's limitations. For example, the sandboxed security model won't let foobarapp.html iterate all files of the local file system. And Mozilla's new filesystem api isn't really available yet: https://caniuse.com/native-filesystem-api
Not sure if there's any "deception" here. Developers just want to write desktop apps leveraging their existing Javascript knowledge instead of learning C++/C#/Swift for each platform and managing feature parity in separate code bases.