This was the first thing I've read about web 3, so I didn't need to grep my brain to find and remove any existing notions about it. As someone coming in late to the party, I agree that installing a browser extension seems like a deal breaker. Web 2.0 was about getting rid of browser extensions. It also sounds like web3 is missing a killer app. For web 2.0, Gmail and Google Maps and YouTube were all immediately useful to all web users. Web 3 doesn't sound all that compelling to a lay person.