ingredients alone give minor buffs ie health.
people woo roleplay enjoy eating food.
it has nothing to do with making potions, but eating food out in the wild.
And given how Bethesda does things, adding it would still leave you griping- because we all know full well how it would likely work: instead of activating the tree putting the apple into your inventory then you have to go through
all the horrific pain and struggle of opening your pack, it would change to activating the tree opening a shuddering, script-driven dialog:
You have selected an Apple.
[Pick the Apple and put it into your pack]
[Eat the Apple]
[Do nothing] And of course being script-driven, this would make picking 3 apples in a row take longer than emptying a small farm in Oblivion did. But hey, so what if it drags things out to a boringly long time frame for simple activities- it't all about the roleplay, right?
Maybe they could also animate changing clothes so when you want to put on a different outfit, the game shifts to third-person and you have to watch as you unbuckle your armor, remove it, and shimmy into the shirt you're putting on in its place. :facepalm: