shamrock7seal
Probably a combination of all three. Icelandair have been playing them at their own game of opening up more niche US routes. In Europe the range of airlines into Iceland now is mindblowing, within this decade it was pretty much just Icelandair, Iceland Express/Wow, SAS and some German charters. In the UK the only routes were Heathrow, Stansted and Glasgow. Now London alone had until yesterday seven airlines serving all six airports. KEF is served by a number of major airlines.
Wizz probably now deliver as many flights and pax to KEF as Wow did in their early days.