So much this.
Potion refills should be very rare outside of the guaranteed boss ones.
It is such a common issue in A-RPG design.
If healing is free and endless, the only counter is oneshotting.
This has already been solved in other games, such as Souls games, and D4 got part of the Souls potion system, with a limited amount of potions going into a dungeon.
Now the refills just need to be addressed.