The industry filters first against people who don't want to crunch or to move: the old hands of game development are almost uniformly workaholics and willing to uproot themselves to a new country for each gig. They are numb to these particular pains. But most people are not, and it shows in the turnover numbers.
The second promise that keeps people in tends to be built around having multiple tiers of employee: the ordinary worker, and the lead/senior/director/etc. - where the higher rank gets more sway and less vulnerability to layoffs, as they are the "core" of the studio identity, and as a core member they hold some more bargaining power and creative freedom. Most of the employees are there to fill in the ordinary stuff - the small props, environmental details, and minor features.
Even with the programmers this holds true: the core technology groups of the large publishers tend to be at some distance from the teams working on a product. These top level people are also the folks that can most easily crossover from high-profile tech in games to high-profile tech in another field. Many of the people who write shipping code that is not the core engine(customized gameplay features, event scripts, etc.) get positioned - willingly or no - as specialized grunt labor, making a career move harder later. There's a lot of little stuff shaping narratives here.
On that note, one of the things that is on the table for game unionization efforts is standardization of job titles.