[matwood]

I can't speak for the EU, but this article was interesting. It sounds like a big part of it is that Ryanair's costs were simply less to start.

https://onemileatatime.com/insights/why-spirit-fail-ryanair-...

[gib444]

Thanks for sharing. Interesting how fuel isn't mentioned once (other comments here have suggested it's mostly to do with fuel). Only possibly indirectly via cost per air seat mile (CASM), but AIUI airlines frequently exclude fuel from that

IMO Spirit's bad business decisions should be acknowledged.