I think they just meant that an Electron app is still at least (half) browser-based, just you're shipping the user a particular browser alongside the app code.
I too have been following your talk on Tritium, so that for the past few years as I have been hand-crafting a new open document engine for the web I have had your use cases in mind as ones that I might be able to solve if things went very well. That engine is shipping today and I think things have gone quite well, so I would absolutely love to talk to you about how we could reshape the landscape if we put our heads together. I feel certain that what I've built could be made into a groundbreaking product in the law world, if only I knew anything about law (not from TV)!
Yes, except Electron apps have the ability to break out of the sandbox because they control it. I take the point that the web stack is used in Electron apps, but it's the other issues, esp. as compounded by cross-browser compatibility that are hard to solve in what most people think of when you say "a browser" context.
That's why 80% of developers use a web based VS Code/Cursor