What is the point of them if you cant equip them/use them in battle? It's much easier to go to the healer outside of battle.

It costs me almost 13k SP to heal at the healer. So if I have some potions on me I just use one, then go fight someone easy (like Buttwing) and use my P Quill to 100% heal for cheaper. Most I get for free through BQ, but if I wanted I could do the same with a 5HP potion, which costs about 4k. It can really add up if you're doing a lot of battling in one day or if there is a boss battle. And of course there are plenty of pets with higher HP and higher healer costs than me. Plus you get EXP and the amulet/tome drops on the easy battles so that's a plus too.

They used to be more relavent when 1k hp was considered really high.