Were Runes not supposed to be replacable?

Im not sure if im misremembering, but I was under the assumption the initial design philosophy was that runes would be able to be replaced by another rune or meta gem. I thought it was only metagems that couldn't be changed after slotted, but I don't understand why you can't change runes on a piece of gear?

To me that seems like flawed game philosophy that you may brick a piece, or a rune stops you from transitioning to another piece of gear because you are not capped on res or some other reason. I think you should not get the rune back, but it should be like World of Warcraft where you can slot another rune in an exisiting rune on a piece of gear, causing the old one to destroy and for the user to apply a new rune in that slot. That seems like a much more fair design.

For example, I just crafted a new chest piece in maps and have 2 runes to use on the chest. I am hesitant on wanting to slot in 20% armor, or life. Im overcapped on ele resistence right now. So lets say I slot in the life nodes, what if down the line Im still using the chest and i change my amulet and now I need lightning res to cap again. WHATS the reason for not allowing the user to replace a rune with another rune?

Runes should definitely be replaceable. Crafting bench mods were replaceable and it was the by far the best system for improving your gear and balance your resistances in PoE 1.

It's sad enough that certain runes seem to be very scarce and that you can't add them to belts, rings, amulets and caster weapons, but them being non-removable was a really bad decision.