When learning any complex skill, the key is figuring out what the fundamentals are, and practicing those, in isolation and small combinations (along with throwing everything all together, of course).

For painting, the fundamentals are usually listed as something like values, shapes, edges, and color.

Some might make a more exhaustive list, for example breaking shapes apart into more “drawing” skills like perspective, construction, anatomy, etc. this is useful because it’s even more isolated things to practice beyond just making pleasing shapes. (I think some use just “shapes” as the fundamental because the breakdowns imply you are painting some sort of realism, which doesn’t have to be the case. Abstract art, or even non realism representational, still uses shapes)

It can be hard to tease some of these apart, but what the parent is talking about, and what TFA is doing, is practicing values and shapes (though the article also has color, this isn’t necessary). all edges are hard edges, so that is removed from the equation, and you can just practice creating something that “reads” (ie, looks like the thing you intended).

If you wanted to practice values in isolation, you could freeze the shapes, and just adjust the value of each shape to explore what effects it gives and if it still reads.

I agree that learning things, like painting, is made more complicated that it needs to be. Check out Marco Bucci on YouTube. He’s a great teacher (his free videos are fantastic, but I have all his courses as well).

If you watch an experienced artist they don’t generally take these individual steps, as experience lets them combine the fundamentals, but you better bet they put in hundreds of hours practicing them.