It's a very good question. Where or what is the niche in the market these days?
I can't see where any profit would really come in a small regional player- perhaps there is a small margin on some of the old Flybe routes from Southampton to France and Exeter to the likes of Paris and Amsterdam?
I sometimes wonder if another airline along the Palmair style - but larger - from some of the more underserved airports might be able to carve a niche or would you be eaten alive by TUI and Jet2? But then, some of Palmair's USP was their small size. It's hard to ramp that up to scale.
I would rather keep my money in a bank and invest in something else 😉