Paper wallets also have one more problem, ink can fade away with time if paper is not stored in proper way and we have such case some time ago in this forum when user ask how to recover missing characters from paper wallet. So if we go in this direction to save our private keys it is much better to use some more durable materials like steel or plastic and engrave private keys in them.
As for ink fading away with time I think you can buy special, military grade ball pens and notebooks that should be a lot more durable.
Regarding hardware wallets you missed very important thing and that is backup of seed - in fact the only thing that we need if device is broken is to have seed and then it is easy to make recovery. However we are back to paper again since most users will write down seed on paper, so key thing is how to protect paper of all possible external influences and from thieves. Only way is to not use it at all and problem is solved, and to protect from thieves every users need to use their imagination.
This does bother me too. In my country it's very difficult to rent bank storage like you see in the movies, I've even read it's something you inherit - they're that scarce, and that would be good place to keep seed backup and generally backups.
One of the ideas I have is to encrypt the backup. You could use offline computer to burn encrypted copy to a disc or pendrive or even write down encrypted version of it.
Problem with ink fading away really exists, but if paper is stored in a way that is protected from external influences (air, dust, heat) and if user do not touch that paper every day ink will last long enough. There is for sure more professional ways as you say, but such military stuff is not something you can buy just like that.
I would never trust bank storage to keep my backup, firstly because I do not like the banks (as well as many who support cryptocurrency), and second reason is that bank sef deposit box is not 100% safe - it can be robbed same as money in the bank with the difference that the bank will compensate the customer for stolen money, but content of the safe box is secret and can not be secured as such.
For all who use paper for backup of seed or private keys best solution is to make few copies, store them on different locations which will be checked from time to time.