So motivate them to not move on to competitors. I don't think companies should cynically take it as given that people only last N years, and will leave for greener pastures once they're trained. They're leaving for a reason, so address that reason.
It's a totally unavoidable problem with our industry.
People get bored working on one domain, one product and one codebase.
And most software shops have one domain, one product and one codebase.
It's pay. It's always been pay.
It's the pay.
> People get bored working on one domain, one product and one codebase.
Yeah bullshit. It's the pay.