Only when you look at them from scenic outlooks. I already showed you an unconformity at the top of the Redwall has deep channels and deep karst filled in with the formation below. You just refuse to acknowledge such and instead wave your postcard of the Grand Canyon around.
Post 35 or 50? I hope you can do better than that. In 35 the bottom layers are folded but the transition is flat. In 50 I see nothing that disagrees with what I have observed. And you pointing out a couple of layers that vary in thickness just begs the question of why every layer doesn’t. We are talking hundreds of millions of years here where one predominant material or set of materials is laid down without ever having major erosions that greatly affect that layer or the layers under it.
Deep water channels are utterly ubiquitous at the surface, even in dry areas, for example. Over hundreds of millions of years they should be cutting the layers over and over, extending through multiple strata just as canyons do today. You should see that evidence of erosion everywhere, not just in isolated locations that indicate very special circumstances.