Most devs, in my experience, are team players. They'll get the grunt work done. But if you ask them to do grunt work for even five years, you're making a big ask.

You might need to pay more to price in the pay cut they'll need to switch gears or the year off they'll need to retrain themselves on related open source side projects.

That being said, there are lots of engineers who get comfortable and shy. You can fill up all your desk chairs in your office eventually. You just won't have a well trained workforce, which is bad for everyone involved.