I'm not as familiar as I should be with the Greek-Cypriot-Turkish triangle,so,I'll try not to be very argumentative on this( I know the historical facts,geographical ones,etc but it does require more indepht study).
That being said, you're right on what you've said, on those economical parameters,but,all is far from lost.If the EU should give up,upcoming players like Turkey, and basically everyone else should just lie down and die.
No,there's still wealth, knowledge, tremendous capability within Europe to fight on,to come back.If we can't do it,NO ONE can do it,and the world will be split between US and China.
If a block of 450 million people (excluding close allies as Norway, or the UK), with a GDP per capita of over 43k (Turkey is at 15.5k),with companies like Airbus, Leonardo,Thales,ASNL,Rheinmettal,MBDA,Spotify ,Lidl, Aldi, Carrefour ,BMW,Eutelsat, ,etc,etc ,with its own space rockets,(Ariane),is already defeated and dying....you might just give up on everything now.