It is not good to hold your coins on exchanges but hold them on a self-hosted wallet. This brings the responsibility of how not to lose your seed phrase because if you lose your seed phrase you will lose your coins.
If there is a natural disaster that flood your town or an earthquake that destroyed the building your seed phrases are, what are the other recovery means that you have in place for you not to lose your bitcoin?
We should backup the seed phrase in a way that no matter what happened, we should still be to have access to the seeds phrase. What are you approaches to make sure that no matter what happened, you will have access to your seed phrase if you are still alive and your brain is functioning properly.
It is good to save our coins in a non custodian wallet because it's unhackable and it's gives you full access and control of your funds while another important aspect to be considered is to secure your sees phrase in a safe place.
In my own opinion,it's is good to store our seed phrase in a different locations for safety reasons, apart from our homes,we can still stored and keep our seeds phrases in the banks. The banks is an institution that will save our funds but not just our funds alone,we can also saved our important documents in the banks as well. Incase of Earthquake, should in case it happens,I think we can choose 5 different banks in a far distance locations that's still within our reach to saved our seed phrases as documents.i think our seeds phrases can be more safer from accidental losses if we stored it as documents in five different banks as banks are a safe house for keeping money and documents. This backup plan has been working well for me for so many years and I believe if you choose to Use it,it wouldn't be a bad idea but a brilliant one.