Here's an interesting snippet, from this
analysis of WOW Air's strategy and network:
Although Wow Air pursued a transatlantic connecting strategy, data from Sabre Market Intelligence shows that 95 percent of its traffic was local to/from Iceland in 2018, hinting it was much less reliant on connecting Europe-North America than its business model suggested.
I was really surprised to read this - I'd had the impression that it was all geared towards transatlantic connections.