In the event of war or societal collapse, bank accounts get frozen, and gold gets seized from vaults. You can last longer by hiding classic cars inside barns and putting Mont Blanc fountain pens and Rolex watches under your bed, but ultimately the ideal asset to have is always going to be a key in your head that unlocks noise, noise which can be stored in all electronic memory and in the cloud. To seize your cryptocurrency, government would have to prove that you have a key in your head, and that the key unlocks X piece of random noise which can be used to retrieve Y piece of cryptocurrency; something which can only really be done using prolonged torture, unfeasible
The maths behind cryptography and the potential of anonymous transactions and cryptocurrency was worked out in the 1970s, and in the ensuring decades became well-known in science fiction, especially among libertarians and anarchocapitalists, which is is why you can see videos of Milton Friedman discussing the idea. The innovation of Bitcoin was that it used a pubic ledger rather than having to rely on a trusted third party (a crypto-bank), which people were expecting to be necessary
It is and has always been taken for granted by people in the industry that cryptocurrency will take over the world. The problem with Bitcoin is that you are betting on that particular incarnation of cryptocurrency to be the one which will take over the world. The public-ledger system create big problems with scalability, problems which might not be solved, and if solved may be solved on another cryptocurrency. If it’s bitcoin which solves those technical problems than it’s bitcoin which takes over the world, and a fraction of a bitcoin becomes worth a fortune. If it’s another cryptocurrency which solves the problems, then people will switch to that, and bitcoin will drop to zero. So to bet on bitcoin is to make a technical bet on that particular incarnation of cryptocurrency solving the scalability problem. In the long run expect to either gain everything or lose everything