We know from multiple studies (e.g., 1, 2, 3) that learning at work improves both job satisfaction and organizational commitment. Both of these contribute to higher productivity and lower turnover.
Many companies use personal learning budgets and some type of "5/10/20 percent time" policy to encourage learning. These are useful but highly dependent on personal motivation and learning habits. It’s often hard for software engineers to prioritize learning over their busy day-to-day work. For example, only around 10 percent of Googlers are using their famous "20 percent time" policy.