Before I knew to countersteer, I was a very shit rider. I needed three lanes to take a right turn as fast as my friends using one lane. I scared the crap out of them. They were like "lean that shit over stretch!" And I just didn't get why I wasn't leaning like them. I was really trying to turn the bars right to turn right, so I had to slow way down to make the turn.
Knowing to countersteer made everything feel so much better.
And I am not convinced that you always countersteer at the slowest speeds. Open to being wrong, just how things feel to me when doing little slow speed parking lot circles.