Airlines have opted and are opting to fly fewer planes with higher ticket prices. It's a price over volume optimisation that seems to be in fashion in many industry segments. [0]
I will note that some airlines have been affected very badly by issues with rebuilding staffing in ancillary services like luggage and airport security. That uncertainty I think leads to them being less ambitious with growth.
0 - https://www.bloomberg.com/news/articles/2023-03-09/transcrip...