I think you got my point. Usually, you don't stop looking at people in the street thinking how great is their walking. Walking is a simple enough task so that in normal conditions you don't see a wide range of abilities. Unlike swimming, playing music or cooking where even in normal condition you can see that some people are incredibly better han others.
An other example that comes to mind are regular airline pilots: nobody wonders whether they are good or bad. We never have to worry that the pilot is unable to fly the plane.
Again, this is a terrible example. I'd say that a good third of passengers are wondering exactly that. (It's irrational to do so, but that's another story.)
And further, skilled pilots can be recognised by their landings, particularly in making soft ones in stormy conditions. Perhaps also in their customer service with witty commentary over the PA.
Divergent, but any skill I can think of will have a distribution of abilities. Some of these skills have a threshold beyond which incremental improvement gives little benefit. Walking example: if you can walk 100m in one go, you are better off than someone who can walk 10m. Likewise, 1000m > 100m. Does 500km give any more benefit than 50km? Maybe, but probably only for extreme use-cases (maybe competitive extreme-distance walking? I'd rather drive!). Similarly with technique - if walking technique is horrible it matter for mobility and injury risk. Beyond a certain level, it probably matters less. And maybe walking extremely well is a visual-social signal, as a marker for someone who is in good shape? I'd read somewhere research done on dancing as a marker of fitness for attractiveness to the opposite sex.
This is obviously not true.