steep learning curve usually means the opposite of what the author wants to say:

"The common expression "a steep learning curve" is a misnomer suggesting that an activity is difficult to learn and that expending much effort does not increase proficiency by much, although a learning curve with a steep start actually represents rapid progress."

https://en.wikipedia.org/wiki/Learning_curve

When writing, consider "challenging learning curve" instead (I'd love other suggestions too).