Lightning will allow Bitcoin network to scale to millions of more users.
The benefit of Lightning is that it enables high frequency micro-micro transactions that can be cleared "instantly" for negligible fees with no chargebacks. E.g. paying intellectual property rights per minutes of watch movie.
Lightning will let machine open channels automatically between machines.
Lightning makes it possible for companies to offer instant use of your payroll earnings up to the current moment with no risk. Charging per unit of time would work to keep contractors more honest and competitive.