The myth is that block planes are the only tool to use for cutting end grain. Let's get something straight here. Bench planes like a smoothing or jack plane work just as well on end grain. [Depending on your sharpening technique, they may work just as poorly, but that's another story.] This is because a standard angle block plane and a bench plane both have an effective cutting angle of 45 degrees.
If each iron has a bevel of 25 degrees, and the bedding angle of the block plane is 20 degrees with the iron bevel side up then the effective cutting angle is 20 + 25 = 45 degrees. While on a bench plane the bedding angle is 45 degrees with the iron bevel side down and so not impacting the cutting angle at all. Ergo 45 degree cutting angle. They are the same cutting angle.
Which means that either a block or a bench plane will cut end grain just as well as the other. The real difference between these tools is how easy the block plane is to handle when chamfering edges or planing in tight spots and how much weight you can get behind the push of a bench plane when cutting end grain.
Now the exception to all this of course is the low angle block or bench plane. The bedding angles here are around 12 degrees which yields a 37 degree cutting angle. This makes these low angle tools the best for end grain cutting because the lower your effective cutting angle the easier the tool slices through wood. But it also means you'll get more tear-out on squirrely woods planing long grain, but hey, that's what scrapers are for.