The real question is, what are the incentives and constraints that Lightning node operators and potential node operators are responding to given their specific context? Bottom line is, those who believe it's worth it are running nodes, and those who don't believe it's worth it are not running nodes. Unless someone not in that context is willing to go to a different context to spin up new nodes, or finance someone who wants to spin up a node but doesn't have the money, there are exactly as many Lightning nodes in operation as the incentives and constraints of the context the person is in is relating to as seems worth it.