For me...

It would be nice if we didn't have to hit the button for each item cooked.

It would be nice if we didn't have to run out of stamina planting stuff.

It would be nice if the "hit box" on vegetables/barely/fax weren't so small

It would be nice if Barley wasn't so hard to see against the black background of cultivated soil.

It would be nice if I didn't have to hit the "E" key 200 times every time I load my 4 windmills.

It would be nice, if I didn't need an "empty slot" to create something when the item I am making has an incomplete stack.

And before anyone says "there is a mod for that" we're talking about the vanilla game here not mods.