and unbreakable doors

God yes.

You need to indicate the difference between a door that is just painted on, a locked door that you can unlock with an appropriate key, and a unlocked door you can open now.

All of these need to be visually indicated at a distance. So you don't waste your time walking up to 100 doors that are painted on.

The problem here is the painted on doors. If they didn't exist, you wouldn't need the indicators.

Know what games don't have yellow paint? Breath of the Wild and Genshin Impact. They do not need it, EVERYTHING is climbable. No yellow paint needed if it's always interactable.

Same goes for objects and doors. If they're always interactable, no yellow paint needed.

The yellow paint is only required when you mix interactivity with non-interactivity.