I'm probably more of a supporter of old-school methods, because in my case I trust my private keys only to my paper notebook. I don't use any other media anymore, and I'm very suspicious of any electronic media that can help save passwords or any other sensitive information like private keys. For me, my notebook, locked in a drawer, is a fairly reliable tool.
I think having a physical copy of your keys is your safest bet to preserve your crypto for generations. Without any digital trace, how would hackers be able to successfully steal your crypto in the first place? Only a burglar will be able to "steal" your crypto if he knows the location of your keys stored in a physical medium. The best practice to help protect your crypto is to exercise discretion. By making a physical copy of your keys and storing them in a discreet location, no one will ever find it.
There are many ways to store your keys securely limited to your own imagination. As long as you follow the necessary security precautions, your crypto will last a lifetime. Just my opinion
