>there is no opportune time
>your coworkers suffer for it.
Yeah that's the cultural difference right there. People just go on leave whenever. If the company is so fragile that it can't survive someone being away for a bit (or sick) then it's inadequately staffed to be resilient.
That said I'm in an industry where replacing someone takes ~6 months so probably above average cautious on resilient staffing
>Are you required to take those 28 days?
Legally - don't think so, but the question just doesn't make sense in that context. Everyone's taking all their leave from what I can tell.
With the constant stream of projects there is no opportune time. On top of that management rarely works vacations into capacity planning, so if you leave it just gets dumped on someone else. You are then disincentivize to take days, because your coworkers suffer for it.