> if I wanted to make my own browser

muhahahaha (sorry). What I am trying to say, is that basically nobody can make a new browser from scratch today (not just a redecorated webkit). The only entities that can create or maintain browsers are megacorporations (Apple, MS, Google) or dedicated foundations (Mozilla).

Now, imagine a parallel universe where there is a standardized API for browser plugins which run in a sandbox (unlike NPAPI). Any startup can easily create bring new technologies to the web platform. You could put the plugins on the OS'es app store and vet them like regular apps if yuo like. Virtual reality, accessing a 3D printer, custom hardware, ... or just better network access and the ability to run a IMAP mail client, a terminal, or a bittorrent client in the browser (without a server).

I'd argue that the "open web" is actually one of the less open possible architectures, and limits what you can do. And the reason for this are business interests of Apple & co.: Why would you sell your app in the app store and give apple a 30% cut, if you could do everything a native app can in the browser? And I also bet some of the restrictions of the open web are benefitting the content industry - like restricting what formats you can use, the inability to use full networking (and to create a P2P "pirate itunes" without central server in the browser), the introduction of DRM in the browser (EME) and so on.