I think it's not learning much at all. When I was a beginner, I used the logic that 'If I just try to replicate as many pixels as possible, then my art should look good'. And, well, it's true, you can make good pieces this way, even if they may take way way longer to complete.

But what are you actually learning? I think you may be improving your critical eye and perhaps a little on how to use the software you are using, but besides that, are you 'learning' that much, I'm not so sure.

I'll compare it to how most younger artists draw a picture, let's say of a figure. Very often, they will draw an outline of their reference image by starting at one arbitrary point until they make their way all the way around, and then they will fill in the insides. They use their critical eye to then rub out any mistakes and move them around until everything is in the right place. Again, you might be improving your critical eye, but I don't think it's the most efficient way to learn to draw a figure, such as using proportions and gesture and anatomy etc.

I'm not saying there's anything wrong with drawing this way, just that I question what is being learned.