So I live in the socialistic hellhole called Sweden, and I'm gonna tell you what unions have done for us: Every swede has 25 days or 5 working weeks with paid vacation every year according to the law. And a employer can't stop someone from taking out 4 continuous weeks during summer. Also you get a 0,5% bonus everyday you're on vacation, that's you basepay plus 0,5% when you're not working. But some unions have 0,8%
If you don't take out every vacation day in a year; your allowed to keep them for five years. If you leave the company before you can use them the company has to pay you your basepay per day plus 5,4% in your final paycheck for every vacation day you saved up when the employment ends.
But If you still work at the firm and haven't taken out your vacation after five years, your boss is forced by law to make you go on vacation. Otherwise the firm will get fined, or the union will take the firm to court.
But I get 30 days because of my union, and when I get older I get more days. I think I get an additional week the year when I turn 40, and again at 50.
Tldr: due to the unions I'm not working 135 days every year