Flame away but I don't really find "healing puddles" to be either immersion breaking or unrealistic(at least no more unrealistic than casting magic spells etc).
Magic healing potions are just that "MAGIC". I don't see why the substance can't be absorbed through the skin and has to be drank in order for it to work.
Because it breaks the verisimilitude of the setting. Potions are meant to be ingested to take effect. Also it requires a bonus action in BG3. In this case you just have to move to a puddle.
I never played DOS because of its reputation of silly mechanics. I had hoped Larian would take the BG3 license more seriously. I was clearly wrong if healing puddles are intentional among other things. I won't be fooled again by Larian in the future.