It’s sounds naive here but keeping a happy troop surely has to be cheaper than risk loosing someone or even more than one.We'd likely spend 10's of thousands getting someone up to speed, would take a couple of years and then the likely of them just nashing off on a whim? No thanks.
The potential for that to happen is always there but if we ignore obvious signs ahead of time then more fool us.
I’ve recently moved purely down to contract changes. The company has changed terms and conditions and have become not competitive so I left. Another person has put in their notice and 2 are looking to reduce their hours and look elsewhere if they don’t get what they want. A massive impact on delivery and avoidable imo. With one email, good will was gone, the room was misread. This is the 2nd time I’ve left jobs because of the erosion of terms and conditions and I would do that again.