I totally agree with this.
We've been looking for mid-level staff that are likely to be with us for years. We like recruiting trainees and bringing them up all the way through the ranks, but also to have a backbone of good quality, reliable staff.
The younger staff we have have a huge sense of entitlement. One had really poor performance, was repeatedly late but wanted a payrise! When we pointed these things out he said "well, if you paid me more I'd have more incentive to turn up on time"! Thankfully, he's hit 30 and has got married and has suddenly matured, so is now one of our best employees - it was a very frustrating period of time though! He was lucky to make it through as he got to a final warning stage before he bucked his ideas up.
I've worked for almost 30 years now, always for small businesses, and the only sickness absences I've seen from colleagues have been the usual viral issues and an occasional more major health concern, like having operations, etc.
In the last 12 months, out of my team of 5, 2 have gone off on long term sick with mental health issues. They're both in their mid-20s, single and still living at home.
We don't give them a stressful work life. Their work is set weeks in advance with realistic and reasonable deadlines. We don't ask people to work any extra hours. They come in at 9am and leave at 5.30pm on the dot.
I have no idea why there is no resilience any more!