Earlier quoted context omitted.
A big difference with Ryanair and other low-cost airlines is that Norwegian stays away from dark UI patterns in their website/app, and also doesn't use the "make it uncomfortable enough that you consider paying more, but not so uncomfortable that it stops you from using it" tactics in general. I think they'll be much better at customer retention.
Perhaps where Norwegian and Ryanair compete on the same routes (which isn't many). But even then, if there's more than a €10 difference in the headline price, most LCC flyers will pick the cheaper one regardless. I think just like with blindness to banner ads on websites, most consumers quickly learn to avoid the dark patterns during check out. To be honest, Ryanair's new web app is actually not that bad compared to…
I really can't see myself getting a Ryanair flight to anywhere where I could get Norwegian, airBerlin, or other LCC that aren't as cheap as "Fly for €6.99" but at least treat you well.