Following on from your posts in this thread (
https://bitcointalk.org/index.php?topic=5259587.0), it seems that you do not understand what a seed phrase is, what it does, and why you should use one.
Because, in addition with a txt file that you can encrypt with many ways and save it in many places, if your hardware stops working, you're a dead man.
This is absolutely not true, and is the entire reason that every good hardware wallet tells you in big capital letters to back up your seed phrase. If your hardware wallet dies, breaks, gets lost, is stolen, etc., then you just recover from your seed and you won't lose a single satoshi.
The reason why the private key can be easily stolen, is one of the reasons why bitcoin will never be a standard currency.
Can you explain why you think private keys can easily be stolen? They can only be stolen if you are careless with them, such as backing them up in text files like you suggest in your opening post.