I do not see the issue, especially since, as of now, there is no way to easily craft healing potions or potions at all, and the general difficulty level is rather high. While I agree that apples do not heal broken bones, a rest does not either. And how potions and spells do that is also pretty shrouded in mystery. What food and water undoubtedly does is give sustenance that can help healing and it is common practic in games that food items heal. So it is all in the realm of authenticity and accepted make-belief.
I recall PoE used food as a resource for resting, which I am fine with. But the amount and availability of healing potions and other options need to be high, if you ever want to break open the classic tank/healer/mage/rogue meta with a party of only 4. Healing needs to be wide and easily available through multiple sources.
If it is bothersome that apples heal, I would say picture them as magically enhanced food items. If spells can heal, food items that are enchanted can, too. For diversity from conventional healing potions I would accept if they would apply a HoT effec rather than a straight heal, which would also give it a tactical aspect.
