or i would do something similar like craving the key on metal or something like this.
There are already 'wallets' available which are made out from metal (e.g. ledger cryptosteel
https://www.ledgerwallet.com/products/ledger-cryptosteel)
paper wallets are easy to deal with.
They may be easy to store. But its not intuitive to spend from them.
Especially not for new members. A lot of people have lost funds because of a change address which they havn't backed up.
on another hand hot storage like Ledger Nano S can be very expensive and vulnerable at the same time.
~60$ doesn't seem too much for me.
Especially if you consider all the pros it has. You get an isolated device.
The private key never leave the device. It is convinient and safe.
While it is true that vulnerabilities have found.. nothing is bulletproof safe.
Vulnerabilities will always be found. In each kind of wallet. This does not mean hardware wallets are bad.
i can print multiple keys with paper and place it all the secure place for back up. i cant do that with hardware wallets. though paper wallets serves best back up option.
Hardware wallets are initialized with a 12/18/24 word seed. This seed is used to restore all private keys.
This seed
should be backed up in paper form. Not much different from a private key printed on paper?