Ok, so US company re-discovered benefits of something that in Europe is mandated by law :) Once again we can see how US is a place to earn money and Europe is a place for work-life balance.
Add 5-7 days of bank holidays on top of that and average Polish employee has at least two or three vacation periods per year.
My own, single data point from this year:
one week vacations in February (skiing),
5 days in April (Easter + 2 vacation days),
one week beginning of May (two bank holidays one day apart + 3 vacation days),
two weeks in August,
one week planned for Christmas (requiring only 3 vacation days).
Fairy typical schedule in my country.
I never heard about a company/employee fined for not taking (as in, employee refusing, not company denying) vacations. It's quite frequent in small companies and/or in higher ranks actually. But theoretically it's just another labour code offense.
However, most companies have an unwritten rule to use up vacation days during the year and don't accumulate them. Unused vacations pay is due on the day of resignation. Nobody wants someone to go 10 years without vacation and then pay them nearly an annual salary in one go.
Some are pushed to their limits every day for a meager wage most of us wouldn't leave the bed for.