I often think of the Noah Smith quote: “Fifteen years ago, the internet was an escape from the real world. Now, the real world is an escape from the internet.”
To return to the gym analogy: a good fitness trainer will help you to safely exercise and grow your muscles. And you will be uncomfortable. But you will be safe.
The job of a leader is not to protect their team from discomfort. It’s to protect them from harm—and to help motivate them to push through the discomfort and harness it for growth.