An on-chain transaction is required to create a lightning channel which holds funds. For every person in the world to open just a single channel in their lifet

An on-chain transaction is required to create a lightning channel which holds funds. For every person in the world to open just a single channel in their lifetime, it would take just about 34 years (with 7 transaction per second, 7.5 billion people, and a block every 10 minutes). This doesn't include the transaction necessary to close the channel to receive the funds back in the Bitcoin wallet.