Most countries in the world don't do the 'depending on what your particular company decides to give'. California recognizes 18 holidays. Average holidays given is 6 (https://money.com/columbus-day-who-has-to-work-why/)
Lately I've seen a lot of 'unlimited' - read as less than your boss takes
Unlimited isn't the worst possible vacation situation, but it can definitely be bad depending largely on your boss.
I took a job with "unlimited vacation" at one company and then AFTER I started my boss "explained" to me that "Unlimited means 4 weeks here." About two months after I started I was moved to a different team new boss. My new boss (same company) had clear deliverables and said, "Unlimited means Unlimited so long as you hit your deliverables." Glad I was moved to a new team.
Lately I've seen a lot of 'unlimited' - read as less than your boss takes
In Europe 20 is the legal minimum