Once you reach a certain size it's quite complicated to let people go, if you need to fire a large amount of people you need to e.g. work out a social plan, you

Once you reach a certain size it's quite complicated to let people go, if you need to fire a large amount of people you need to e.g. work out a social plan, you can't fire performance-based unless people grossly neglect their job responsibilities. For smaller companies with less than a few hundred employees it's easier of course, but once you're in unionized territory firing becomes a process that the management needs to work out with the employee board.