"According to the docs, the cost of "a single network hop" is negligible in most cases"
I'm sure Wayland fans would disagree with you here, as I'm pretty sure that was their gripe with X11.
I don't think anybody will ever convince me that these are "desktop apps" when you're just bundling a web server, with a web browser, and your trash javascript together.
I also don't understand why a browser needs to be 300MB either (well, I do, the browser is effectively a virtual machine with it's display, network and storage stacks). It's a shame no browser lets you disable many of the current webs "features"... All it should do is download the markup text (and pictures) and draw it