No, lowcost companies don't earn more money than those companies. Read the financial reports, they are widely available (hint, LH for example made more than 2 billions euro profit, wizzair around 300 millions last year).
All the companies mentioned above can withstand 6 months without flying. The thing that sets Wizzair apart is a much lower cost base and the lack of long haul operations.
All all of them are and were doing repatriation flights.
And those companies are far more valuable to the local economy than Wizzair, a company with the headquarter in Switzerland, where they pay their taxes, will ever be to Hungary. Hungary will not bail Wizzair, firstly because they will not need to be bailed out, secondly because they are not even an Hungarian company.
BUD airport is nothing more than a fart compared to LHR, CDG, AMS or any other major airport.
I am not saying Wizzair will go bust, they are actually one of the most solid airlines out there, but from here to hiring again is going to be a long step.