Good points
The runway application will be rejected and frankly it would make little difference in the short to medium term considering the impact of covid on aviation.
Other contributors have proposed old chestnuts like Easy and now Wizz coming to the airport,I'm afraid these are non starters.Even with a runway extension the sun routes would be limited to the Med,Tenerife would not be reachable with a full load.The airport owners missed the bus years ago for airport expansion,with capacity opened up at other regional airports Southampton future looks very uncertain.