You can't have consumers without producers. Dev tools are an integral tool to building websites and webapps today. They're still receiving considerable investment from browser vendors. I see new features in almost every release.
I believe this is how iOS development works.
Admittedly we are very far away from this scenario, but let us not delude ourselves into thinking (a) that it's impossible, or (b) that it's not in Google's interest to do this once they are confident enough in their market power.