Love Jet2 but I have to concur.
Flight only pricing in the school holidays is now crazily expensive. For example, a round trip to Malaga for one person is costing £500-£600. Those are not the prices of a lo-co, though I concede prices are higher everywhere. It is now significantly cheaper to fly with Ryanair (wish they opened their bookings earlier) or fly a scheduled carrier where that option exists.
I have a flight only booking later this year and have booked with TUI who were significantly cheaper than Jet 2.
They must be doing something right though and maybe focussing on the holiday brand is the way forward.