Living in Florida, flights via Norwegian weren't really a viable option for us -- but I have NO doubt that their existence exerted downward pressure on the prices other airlines charged.  For that reason alone, I'm disappointed to see them shut down their operation.

The real pity is that they might have succeeded if the prolonged 737 Max grounding hadn't happened when it did.  Maybe someone else will take up the challenge.  I know Ryanair has been threatening to do so for a few years now . . .