Opening the inventory places the cursor in roughly the center of the screen. Navigating using the D-Pad becomes much more difficult, as the crafting menu or container you are using will offset the cursor's relative position.

E.g. opening a furnace places the cursor just above the top row of your inventory. Pressing any direction on the D-Pad moves the cursor to the furnace input slot.

In MCCE, opening the inventory/any container placed the cursor on the first slot in the hotbar.