The old tricks
Older workers know all the tricks managers use to extract value from workers and spit them out once they are past their use by date (approaching mid 30s).
It's much easier to scare a young worker into an unpaid overtime or make them do more work than they should.
Young workers also think they have infinite time so they are less likely think long term about their future, because "they will have time for that".
When the whole team is young, just make sure everyone goes to a pub after they finish at 7pm. They'll have a "good" time and think everyone is in the same boat and such grind is completely normal.
Or maybe this is just my imagination?