I believe the idea is if you wanted a client built with C# Winforms, wxWidgets, JS+HTML or anything else they could all run against the same backend server.. So it'd be more flexible than Electron in that you wouldn't need to use web technology at all, if you don't want to.
Whereas if you build starting from Node.js (or Deno I assume) you can skip the Chromium part. Instead of packaging Chromium with your app you assume that users have a browser and can use that to talk to your app.
The benefit of using Node.js is you don't have to use a different language for the backend. It helps.
BTW. "Electrino" in the linked-to article seems interesting too.
The additional benefit of this approach is that you can then build your application such that it works with all standards-compatible browsers, such as Firefox.
That's not a benefit - that's a down-side. When writing a front-end for Electron, you only worry about 1 browser and you have a guarantee that it will work the same way across every OS.
If you have to write a front end (website) that works with more browsers, you have to put in moro work.
