This is a great point. To condense what you said a bit: the dot-com bubble followed the democratization of stock trading (which itself got a technological assist from the internet). Lots of people, myself included, who never bought a stock start using online trading accounts. The housing bubble followed the democratization of home buying. Lots of people who never had bought a house before (or a second or third house) start buying houses.

The question I've been asking for a while now: what's the next great financial innovation that's going to revolutionize access to some market to which average people don't currently have easy access?

I want to be on the upside of the bubble.