It made sense during Legion. Due to their rarity and randomness, I believe this was done as a sort of preventive measurement.
They should make it able to obliterate them at the forge or something at least. That would still eliminate the risk of accidentally selling or destroying them.
Artifacts take 1-4 slots, depending how many you’ve obtained. Bank has 7 bag slots, if you buy 30 slot bags, that’s +210 slots, I’m sure you can find a spot for your artifacts.
What, are you going to destroy Doomhammer? The Doomhammer?
They don’t allow you to delete them because people would later ask in tickets to get their artifacts back. You need to have an artifact weapon, some times even equipped, to unlock other skins and color tints for that weapon.
You don’t need them on your character, you just have to have them, doesn’t matter if in the inventory or in the bank. All it matters that the item belogns to your character. Also you need to have the artifact weapon equipped to unlock Balance of Power and Hidden base skins.
Also third party guide doesn’t prove anything. I already see that it doesnt’ list all of the requirements for some weapons skins.
Every hidden appearance drops as an item, you need to use that item to unlock the appearance. In order to use the item you need to have the artifact weaopn equipped because it uses special animation that changes your current artifact weapon into the new aquired look.
The last quest in the chain requires you to equip the weapon for the ritual. I did it on my alt a week ago. You can’t use the special ability you are given without the artifact weapon equipped.
Also I just remembered you need artifact weapon equipped to unlock the Upgraded one at the and of class campaign. Again the reason is the special animation that uses the artifact weapon.
I levelled quickly through Legion on my first character just before BfA came out and I did try to delete the Artefact Weapon as I’d decided I couldn’t be bothered to go back. But then I changed my mind, went back and finished the Class Hall storyline. I didn’t realise beforehand that you need the Artefact Weapon equipped at certain points.