I’m also Dutch and I still occasionally use it when I want to be polite to an older person I do not know very well, or to someone who is in a position where I want to show a certain form of “respect” (higher social standing?)

That is probably also why the government uses “u” in its communication. It is proper to be seen as being respectful to your citizens. And saying “jij” after “u” is less likely to offend anyone than saying “u” after “jij”

The rules are a bit vague when you are supposed to use it, and most people will go “zeg maar jij hoor” (you can say [informal] you) after you start with “u” (formal you)