There’s certainly a place for truly native apps, but there are also a lot of reasons companies keep picking Electron. Efficiency is just one consideration.
They could, using Wasm, like Qt, Blazor Hybrid, Uno Platform, Avalonia.FuncUI. Electron is efficient for devs, but inefficient for users, being a memory hog, especially on low end devices.
They could do that today, but do they? I can’t name one app that uses one of those to run in a browser. I can name multiple highly successful apps that use Electron.
I seriously doubt the approach of running a native desktop application in the browser would give you performance or usability as good as running an actual web app.