1. Someone could find it and steal it.
when you have a valuable item, you must adequately protect it by securing your private key in a location where you are confident that nobody can quickly access it. It will be impossible for anyone to steal it if it is securely secured. Since you are aware of how important bitcoin is, you are also aware of how to safeguard it so that no one would ever guess that you have secretly stored your private key there.
Additionally, try to avoid disclosing your bitcoin holdings to everyone, you don't have to tell them everything. Your investment should be a secret at all times. You become more open to assault the more you reveal about your bitcoin possession.
3. You lose your seedphrase and never find it again, or you forgot where you hid it, etc
why wont you be able to recall where your key is kept? i cant just forget about where a valuable asset is kept. It's advisable to often check the location where you secure your key. You shouldn't lock your private key away and leave it laying around. Furthermore, it's preferable your key is secured in different places rather than having it in one place.
4. You or your wife/spouse do some housecleaning and accidentally throw it away.
It's best you educate your family members about bitcoin. Your wife or spouse should be aware of bitcoin, cryptocurrencies, and how you protected your key. If they discover the private key while cleaning the home, I'm confident they won't toss it away after they see it.
5. Can be destroyed by fire or a natural disaster.
If your private key is properly secured, it won't be able to be destroyed by a fire incident. Simply carve your private key onto an iron steel so that it won't be destroyed in the event of a fire or water accident. I advise individuals to safeguard their private keys using that way since, as far as I'm concerned, iron steel cant be destroyed easily.