The first post didn't use it only to mean progress is slow. Version control software is no subject that takes much time to learn. The problem is that if you want to use it for the first time, it takes time to wrap your head around it before you can use it productively.

I don't think the progress on learning R is much slower than the progress on learning Excel but learning R is harder. You can use Excel while have relatively little skill at using Excel.

Climbing a steep mountain takes more effort than climbing a mountain that isn't step. It doesn't necessarily take more time.