Once you deposit something, be it a painting with a museum or physical cash with a bank, you no longer actually own the asset
the asset is owned and held by the entity in your name
but in reality all you have is a slip of paper with an IOU written on it
simply because you “own” the deed to a house, doesn’t mean that you can necessarily physically stop people from squatting in the actual physical house
the best you can do is call the cops and then hope that they’re not too busy or understaffed to respond immediately
if they never end up showing up, do you really own that house?
the same goes for any other physical asset
if someone breaks into your house and steals it, then you don’t technically “own” it anymore
ownership of digital assets is differentiated from ownership of physical assets because the ownership of physical assets must be enforced by law, and when the law fails, must be enforced by physical power, whereas ownership of digital assets need only be enforced by the immutability of the ledger, which as far as we know and in the case of the blockchains considered most reliable, is absolutely perfect
your ERC20 nft may or may not be completely worthless
and you can potentially lose it or get scammed out of it if you’re not careful with your wallet
but if you’re not stupid, then to the best of our knowledge it can never be outright stolen.