>> that Google spends >$1B/year to develop.

Isn't this downright crazy when you think about it? Seems like we need to start from scratch. Create a minimal bytecode (like webasm or whatever) that writes to a virtual frame-buffer of sorts, and has keyboard/mouse inputs. Then content is distributed as compiled byte-code apps. All the fancy stuff you want in your app has to be provided by the app creator, and not essentially using the browser as a library.