When using a prepaid card, the phone number is anonymous. Moreover, no one uses the LN wallet to keep their savings, only for small payments, settling the bill with friends at a restaurant, etc. Larger amounts of course belong in the HW wallet. It's not a solution for die-hard bitcoiners protecting their privacy. It's a solution for regular people who already have all their sensitive data on Facebook anyway. Someone has to manage the node, maintain the channels and create new addresses. How could this work without collecting numbers?