On one hand, the Lightning Network needs block space to open, close, and occasionally rebalance channels. Validity rollups offer a more efficient way to use available block space, and validia chains offer a straightforward and significant expansion of block space (with some security tradeoffs). And the ability to create new execution environments on validity rollups and validia chains opens up the possibility of evolving the Lightning Network in ways that can improve the security, privacy, and usability of the network.

On the other hand, validity rollups and validia chains need a trust-minimized way to quickly move funds between chains. We are already seeing the Lightning Network serving this purpose for bitcoin sidechains such as Liquid and Rootstock. Additionally, even the highest throughput examples of these rollups and validia chains won’t be able to reach the levels of scale currently supported by the fiat payment giants, all while remaining secure and decentralized. A payment channel network such as Lightning could be what is needed for these protocols reach global scale.