Granted this is not the only reason people fly but the migration of lots of people in central Europe to the UK + Ireland as part of joining the EU is what gave the economic rationale for Wizz to exist originally. Georgia, Armenia and Azerbaijan are not EU members, their citizens generally do not have the right to live and work in the EU. I imagine that entrenched interests will make life difficult for foreign LCCs who try to set up locally with a non trivial operation.
Baving said all that many network carriers flying to thsse countries badly need some competition to stop their fares being so eye wateringly high.