It is not about the wallet, but how you use it.

One could use electrum on an old desktop which they do not use any longer and do not connect to the internet at all. If they securely generate their keys on it and back up their seedphrase, maybe with an additional passphrase, this would be more secure than just opening electrum on your regular mobile and creating a wallet, and could be as secure (or more) than a hardware wallet.

How you back up your seed, How you access your wallet to transact, how you interact online all contribute to the security of your asset.

- Jay -