That you should “always be learning” is absolutely true. It helps with neuro-plasticity and keeps you engaged. That said, as a manager I find it hard to get direct reports to accept sometimes that it is not only okay, but required, by me that they learn new things. I do what I can to encourage it, offer to buy books for people, give time to do online course work, etc. They often complain that they don’t feel like the…
Tie it to deliverables, like reporting back to the team about the content or giving seminar style talks.
That's a great idea in theory because tackling a real world problem tends to motivate towards a real world solution.
However, learning invariably encompasses failure which rarely measures up well with typical (if arguably useful/useless) performance metrics that developers contend with.