Ah, Duo.
May God bless her and all who sailed in her.
Plus I would add that fuel prices are about twice what they were back in 2004 or so, while average yields have if anything fallen thanks to increased low-cost-carrier penetration, so the scope for profitable flying is even more reduced.
From memory, Duo's breakeven load factor on ~2 hour sectors was about 70% at £100 net yield. I would be utterly astonished if a 50-seater could come anywhere near that breakeven today.