Custodial lightning works great, but it's going to become ever more regulated. Nothing wrong with regulations per se, but the danger is they will apply constricting regulations that will make lightning banking useless: ZBD for example has ridiculous limits like $250 per transaction, not more than $1,000 in the account, etc. It puts us in a position to make Lightning irrelevant.
In which case, Fiatjaf is right, that we need to start thinking of alternatives.