Stools are atmospheric and Gothic series was the first to start using this system, iirc.
It adds to the immersive and realistic world, where you see NPCs doing behaviors like sitting, sleeping, eating or working,
When you interact with them rather then a Blacksmith just standing at a Forge you see him making a weapon.
Potions are mostly there until you can get the upgrades, like Regen for Mana or Efficiency for Endurance.