The root cause is because the value of the money is being stolen, and people generally will avoid storing anything where thieves steal. All government currency like USD, EUR, JPY, and others, have this property where the value of the money decreases as the respective central banks expand the supply. This has been more obvious the past few years, but it's much more obvious outside the western world, in developing countries.

In places like Turkey or Argentina or Nigeria, the local currency loses value quickly and "investment" in the sense of avoiding theft is a necessity to survive. This is not investment in the Biblical sense; the investment in another asset is really a search for better money.

As Christians, we need to think about these two types of investment. Are we investing money in excess of our needs, or are we "investing" because we don't want to get robbed by inflation?