It depends of how the company behaves. It's no different than with any other employees.

Give people the feeling they are part of something, that their day to day actions have a meaning, and enough money for their trouble, and they'll stay.

Say "we are a family" in your speeches and write "values" on the walls while you are just fitting cogs in the machine while optimizing for numbers and they will leave, or do the bare minimum they can if they need the cash.

This is not something you can fake. Not for long at least.

So it's not related to apprentices.

However, apprentices will more likely fit in your culture, accept changes, etc. Because they grow with you.

I'd say there's 2 main groups of people - those that have been there 20+ years and aren't likely to leave and those under 30 that started as grads or interns and have been there a few years. I don't consider myself particularly loyal, I just happen to like the work and team I'm on and if that stops being true I look elsewhere.