Hardware wallets are also exposed to various threats such as fake versions of wallets (fake Ledger Live) or phishing (fake Trezor sites), and clipboard malware. But this is not a weakness of the device but of each individual user who uses it.
I'm also concerned about things like possibly insecure RNG for key generation and bugs at the software or firmware level. More than anything else, I'm worried about supply chain attacks.
The ideal for long term storage is a method that leverages open source software, general purpose hardware, and a source of entropy than can be verified.