First of all, my condolences...
In this case, the “fault” of the banks is only a small part... In addition, the government of the country is obliged at the legislative level to implement mechanisms for protecting the deposits of the population. For example, in Ukraine, the concept of a “fund for guaranteeing public deposits” has long existed, a state mechanism that forces banks to create insurance funds that, even in the event of bank bankruptcy, allow the funds of private depositors to be paid out.
Well, the main thing - unfortunately, this story is that the population for the most part has outdated habits and does not look at alternative options. Imagine if this money was buried not in the yard, but for example somewhere in the forest, or to a depth of 2 meters! The money is either lost for many years, or another person will find it. Solution - tell your relatives about investments, about cryptocurrencies, influence the authorities - to reform the banking sector