In theory, it's possible everything including a hardware wallet can be hacked, but a hardware wallet is one of the safest ways to hold your coins. I have a hardware wallet, I don't fear it will be hacked, but I do worry about people somehow will find the seed words I have written down, and steal my coins that way.
It is not only in theory but it is real and can really happen, mate. A little fear sometimes is needed to make us be more alert and careful in saving it correctly. Nowadays, hackers become smarter. They always find new ways to steal crypto user assets. So, get to know everything that may be an interstice for them to steal your coins.
