What makes email so versatile with little rent-seeking is that it is a decentralized protocol. Companies that want to provide services involving email cannot do

What makes email so versatile with little rent-seeking is that it is a decentralized protocol. Companies that want to provide services involving email cannot do so by owning all your contacts or data (like YouTube, Twitter, etc.) — they must offer competitive services. And all because you can exit easily. More things need to have this ease of exiting with all of the data (cryptographically guaranteed): banks and financial services, social networks, content distribution systems, etc.