Why did you limit the options to black and white? Which means of security of bitcoin are hardware wallets and paper wallets, there are many options with high security and the most reliable.
Paper wallets are used for gifts and for storage when you want to move to a country or other item, but they are not suitable as a way to store all of your savings.
You can buy a phone at a much cheaper price than device wallets and convert it to a solid device.
You can also use an old computer and turn it into secure hardware.
You can try USB and open source OS.
Unless you know what you're doing, the bolded lines may have even more & worse security holes than a paper/hardware wallet.
Why isn't a paper wallet suitable way of storing all savings? I mean, as soon as it's created and stored the right way, it's just as safe as all the other methods when created & stored properly.
There are so many possibilities of losing your wallets with every method that there's no
perfect way to store them properly. You could easily lose your computer/USB/phone in a fire or if the disk inside the device fails without the possibility of recovery. Even our mind has flaws: you could simply have a bad memory loss after an accident and there goes
everything you had.
I stored some of my BTC on paper wallets for many years without touching them and had zero issues when transferring them back into a hot wallet.
You'd never catch me doing such a thing.
And bank vaults are a dying breed at least where I am. The nearest one to me is about 150 miles away and they're closing at a fast rate.
If you cannot properly store very important data on your own, then the worst thing you can do is give it to someone else to do it for you imo, lol. While you enjoy your life on a sunny beach, there may be a few guys trying to decrypt your wallets behind the scenes.
Or the government itself, if they consider it's worth it.
I barely trust my own storage & encryption methods. Knowing my wallets are in someone else's hands, even encrypted, would constantly stress me the hell out.