It can honestly be annoying, if you're not privvy to it.
I remember years ago needing urgent support for some bespoke European hardware we were developing software for. When we called support, we were greeted with a phone message stating the company was closed for the entire month due to vacation. This was not a one-man operation; the whole office closed for a summer holiday. We thought it was a joke.
Needless to say we started to look for a new vendor shortly thereafter...
My advice is don’t ever buy anything that might need support from New Zealand between 24 Dec and 5 Jan. The entire country is just about closed (other than non-niche consumer stores).
Many companies force staff to take vacation days during this time, and there are four (yes four!) public holidays during this period.
I mean, that's not usual at all in Europe either.
I'm surprised, typically we don't all take vacation at the same time, but stagger it.