do you mean a hardware wallet?
Hardware wallets and most software wallet generate keys by a 12 or 24 word mnomonic. They do this because it's easier to save 12/24 words on a piece of paper for backup than some random long lower and upper case letters and numbers.
Your bitcoins are fully safe however. It's almost impossible to crack even the 12 words because there are over 2000 combinations for each word and also the order of the words is important. If it was 6 words then it would be very insecure and easily crackakle but 12 words is near impossible.
You are absolutely right, because writing words on a piece of paper is much easier than a multi-digit secret key. That is why I still use the Coinomi wallet mobile app, although it is much weaker than the hardware wallet. Nevertheless, I believe that secret words are the best way to secure your wallet.