> I'm not too sure my understanding is accurate, feel free to correct me. OK! :P In a layer 2 or lightning network, there may be hubs operated by e.g. Coinbas

> I'm not too sure my understanding is accurate, feel free to correct me. OK! :P In a layer 2 or lightning network, there may be hubs operated by e.g. Coinbase that handle millions of users, but the hub will need an open payment channel with each of those users in order to minimize the required trust. That means that the scaling bottleneck described in the top post is still an issue. It's useful to draw a distinction between decentralization of network topology and decentralization of power (the ability to decide who has how much money). If Coinbase runs a lightning network hub with millions of users, the network topology is centralized, but if the system has been designed correctly, Coinbase cannot steal any of the lightning network funds (power is decentralized). They could require KYC and would be able to temporarily block a user's transactions. But if people aren't happy with how a hub is behaving, they can just stop using it, and switch over to a different one. It's possible to hand complete custody of your coins over to a third party, and let them manage transactions internally. This scales really well, but then it's not really a lightning network anymore (power is centralized; they or people who hack them can run off with everyone's money). Ethereum (not Bitcoin) has plans to scale their base chain via improvements from proof of stake, and eventually via sharding the base chain. Block size increases factor in as well. These improvements can each multiply with the large factor provided by lightning-network-like things (Ethereum's equivalent is http://raiden.network/ http://raiden.network/). Much of this is still undergoing active research, so it's not all a given. I haven't estimated the numbers, but this all eventually could take us quite a bit beyond 20m users.