Yeah, I completely agree. There are already some services in this space trying to combat filter bubbles and walled gardens, Akasha [https://akasha.world/] for social networks, DNN Media [http://dnn.media/] for news and Lemon Email [https://ipfs.io/ipns/dapp.lemon.email/#/] (dApp and the full beta version) for email system. The last one is completely in line of what you're talking about. I like the approach through blockchain systems because, if used properly, they have the potential to become direction in favor of democratization and decentralization of information.

Set up Akasha out of interest and it does seem really promising. Thanks for the tip!

Lemon Email looks really cool, thanks for sharing.