Cold Storages are generally considered the most secure type of platforms to store your bitcoin, it's basically because they don't always have a live connection, wallet is online only when you connect the hardware into the system.
With an airgapped device cold storage you never need to connect your private keys to the internet. You can create and broadcast your transactions on a watch only wallet, using the wallet that contains your private keys to but sign tx, which does not require internet connection to do.