If you have assets in a bank, stock market, investment platform, 401(k) or other pension then there are a number of risks that threaten not only the existence of those funds but your access to them.
First of all, don't expect to hold onto them unless you go along with the government's game of Simon says. For example, there is a good chance that you will be forced to get digital ID to access these in the future.
Vietnam is an example of what is likely to come soon, where biometrics were made mandatory to access all bank accounts. The 86 million accounts which weren't biometrically verified were frozen and are now being closed. Transfers equivalent to around $390 or more also require biometric verification.
Many in the western world have also had their bank accounts frozen or closed for perfectly legal political views. And now when you move or withdraw money you may be asked what the purpose is and the bank may deny your request if they don't like your answer (just one example). Banks are also required to report anything deemed suspicious to the government.
If such restrictions can be applied to bank accounts, there's no reason why they can't be applied to accounts at stock exchanges and accounts with 401(k) and pension providers.
In Hungary and Poland, all private pensions were seized by the government and nationalized, leading many to accuse the government of stealing their pensions. Existing state pensions aren't safe either, as they are often considered unsustainable due to unchecked government spending and aging populations.
Banks and pension providers can also fail, as we saw in 2023, and US banks have continued to fail every year since then. While on paper there are often guarantees to cover such events, these usually only cover up to a certain amount, and these may not be honored during a financial crisis.
So... should I start stashing my cash under my mattress?
Better to stash precious metals since they won't lose their value. Of course there are other options so make your own decisions based on your own assessment of the various risks involved.