The benefits of achieving a so - called «elite» status vary, but can include access to lounges (regardless of travel class), a bonus in elite qualifying miles when flying in first or business class, the ability to
reserve better seats including enhanced economy class, free or discounted
upgrades,
priority in standing by for a different flight,
priority in not being bumped if a flight is oversold, fewer or no nuisance fees,... well, you get the picture.