They should have some more security features so that even if someone gets access to the seed, funds can still be not moved.
Both Ledger and Trezor do have a feature that does this. It is called a "Passphrase". Essentially, in addition to requiring your 24 word seed, you also need a user set passphrase to unlock the wallet. The passphrase can be anything from a word to an entire sentence or a complete jumble of ASCII characters, up to 50 characters for a Trezor or up to 100 for a Ledger. You can also set up multiple passphrases with the same seed to unlock multiple different and separate wallets. Be aware that if you forget your passphrase, your funds will be lost forever. It is good practice to back up your passphrase non-electronically and separate from your seed phrase.
There are instructions on how to do set up a passphrase at these links:
https://support.ledger.com/hc/en-us/articles/115005214529-Advanced-passphrase-securityhttps://wiki.trezor.io/Passphrase