1. Ease of building and distributing packages with Electron-Builder. I'm able to build for all three operating systems on my Mac, took a few hours to set up.
2. Access to the vast NPM library for all sorts of functionality.
3. Ability to use CSS libraries for styling. I'm no designer so it saves me some time. Collate uses Bulma for styling.
From what I've seen, users are more than happy to have an application that solves their need no matter what it's created in. Most people don't really think about file sizes, or the fact that Chromium is packaged with Node, they just want their problem solved without visual or performance hiccups.
If it wasn't for Electron, Collate would be a very different application or non-existant. I think people need to look at Electron as opening the door to more possibilities.