Every month, your employer transfers Bitcoins into a time-locked address that can't be transferred out before you reach retirement age. You have the key to the address. You can verify the transfer on the blockchain.
No middle-men. No funny business. No brokers with pyramid/eyeball shaped logos. No "oops we went bankrupt and lost your retirement." No bail-ins. No raising the age of retirement.
Just Bitcoin.
I have a bitcoin wallet address which is exactly for this purpose. There isn't much in it but it i constantly keep adding to it whenever i earn some here and there. My aim is never to touch this until i retire. Hopefully this will be enough to live comfortably and take care of my family when that day comes.
I'm quite excited for what the value of bitcoin will be then.