Just to throw a scenario into the mixer:
Going back to the 1980s, prior to the liberalisation of the European aviation market, routes were dictated based on bilateral relations between different states. It allowed the big players, such as British Airways, to rule the roost in the UK airline market. It enabled, due to a lack of competition on key routes, to charge excessively high fares.
When the likes of easyJet and Ryanair started their hyper-aggressive expansions, national carriers became squeezed out on short haul and now struggle to compete and turn a profit. Passengers less interest in service and quality, instead just wanting to get from A to B in the shortest and cheapest way.
I work for a UK airline, which is usually the 2nd or 3rd player on most, if not all routes. Could we go back to a situation where certain governments could prevent more than 1-2 non-EU carriers to operate a certain route, to enhance the chances of their home carriers and as such protecting their jobs? By EU law, a state cannot 'sponsor' an airline - this would be an indirect way to help their residents.
Further afield, there are restrictions between flying to places like Rio de Janeiro and Moscow; the latter which easyJet at one time were able to operate at the expense of Virgin Atlantic, but only up to double daily. The former is an extremely expensive route in relative terms, as there is no open skies agreement, to my knowledge, between Brazil and the UK, as such preventing competition.
The losers are passengers, who will see an increase in fares and employees, as Ts & Cs will be further stretched.