the Load Factor on Jet2 flights during the summer months has always been 90+%.
And well it might have been. But to pay for the minimum facilities to enable those flights to operate needed many, many more flights to pay for them than actually operated, and not just in the summer months.
It has often been said that the minimum passenger movements needed to make a profit with providing those facilities is 1m 1-way movements, and it's probably true.
Once an airport admits that it cannot achieve that, and refocuses on aviation businesses that need a runway and infrastructure but not all the stuff that goes with tour operator charters, a good management can run any licensed airfield profitably.
It's not a matter of "turning it into a freight terminal", for example, it's a matter of encouraging forwarders to set up shop, which in turn leads to freighter operations, as well as GA, helicopter work specialists, maintenance....you know the rest.