Minecraft Theory
What if Steve is a "savant"? He can create End Crystals and pull off feats other mobs couldn't even dream of, yet he doesn't know how to craft chainmail; he simply can't wear chainmail under his armor or put on an elytra over it. He can lift infinite tons of weight, yet he only ever carries items in stacks of 64.
There’s also a theory that Steve is essentially in a "semi-Creative" state. It’s this Creative-mode nature that gives him the strength to lift infinite tons, go years without sleep, withstand massive amounts of damage, and so on—even though he can still die from eating berries or starving. In other words, even in Survival mode, Steve is constantly in a semi-Creative state.
What do you think of my theory?
Don't be too harsh—I'm not very well-versed in Minecraft lore.