Non-custodial wallet or self-custodial wallet. You need to use a correct term.
I know all these terms. You can also call such wallet self-hosted.
A self-hosted wallet refers to a type of digital wallet that is hosted and controlled by the user, as opposed to being hosted by a third-party service
You can also search for it online to know that I am correct.
They are related but not quite the same.
Non custodial wallet are wallet you are in control of your private key
And no third party can access your funds.
Now here's the twist. Self hosted are non custodial wallet where you run your own server( connected to your own bitcoin node)
Thus all self hosted are non custodial but not all non custodial are self hosted (example people that rely solely on third parties server)
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
A flood may likely float away even a durable metal plate.
And for that you can add a paraphrase Incase it falls in anothers hand.
One of the option is to save your backup in different locations
With them been broken in portions.
Or save some words in your brain and leave some scattered online (risky but can mitigate the risk of flood).