as someone in his late twenties from the netherlands, i roughly have the same experience. The recreational drug use has more to do with age in my experience then workfields. Most people i know who did softdrugs casually stopped doing so once they either settled down or got kids.

It might just be my enviroment, but alcohol use is rampant and also heavily culturally ingrained in my area. (i live in the southern part of the netherlands. Drinking during dinner is not uncommon for example, even on weekdays.