A lot of people want to stick around to complete a project as it looks good on your CV. Particularly at a junior level. From my experience (in games) it’s also

A lot of people want to stick around to complete a project as it looks good on your CV. Particularly at a junior level. From my experience (in games) it’s also quite intoxicating at the time and you get quite emotionally invested in supporting the team and fixing issues. In particular crunch is partly enabled because you get close through the adversity. You usually don’t get much opportunity to take stock until afterwards being so caught up in the moment. It’s pretty common to get a rash of departures right after it all calms down.