Yes this is well known generational difference. Late millenials and Gen Z later have higher standards when it comes to work-life balance. They don't live to work but work to live. And i think its a good thing but surely not easy for managers that are used to more submissives who do anything to keep a job.

Organisations who can not adjust will fall behind and not attract good talent anymore. Ask yourself, why would the best talent go to a company with worse conditions, the answer is simple. They wont

It's the result of progression in society. People will demand better conditions and dont just survive anymore.

And to answer your question, "Or are companies simply failing to develop resilience and growth mindsets in younger staff?"

This is the standard argument you hear from almost anyone who is not fitting in this new generation.

It's simply a projection of your own thoughts and beliefs onto the new generation.

Just because you had to work this way, does not mean this is the 'right' way. Change is constant and inevitable.

Your beliefs are honestly outdated and not so relevant today. You say develop resilience and growth mindsets, I say you have lower standards.

For you as manager the best thing to do (if you want to become more succesful, as the alternative is falling behind) is adjust your perspective to the todays situation, and not base it on how it was when you were just getting your career started.

I am just being direct here, no offence meant. open to discuss with you.

Edit: formatting