Luton has no chance of making it to number 3 unless a major enlargement happens and T2 is built. The pandemic and its associated collapse in air traffic, along with a potential CO2 tax on aviation leave significant uncertainties for any investor.
The Dart has been a big enough adventure for now. Luton needs to focus on getting itself back to 2019 levels of traffic, before any of us even dream of LTN starting major new building work