Apple flesh texture

Why does the texture of apple flesh change from bottom to top? The top is a lot easier to chew, looser and more watery. The bottom half is harder and crunchier.

I can’t think of other fruit that change in texture like this, why apples?

Something to do with gravity as they are growing, perhaps?

They’re not tree ripened. It’s not an issue if you leave them on the tree to ripen. Pick them early like for the grocery store and they never finish growing properly.

Pears are usually the opposite - sweeter and more juicy near the bottom, and firmer at the top.