There are several reasons why invest in physical gold bullions. Most people buy precious metals to possess a financial asset that never loses its value. For this reason, gold and silver have been used as currency by many civilizations. Gold, for example, has been valued by different cultures around the world for over 5000 years. Gold has been used for multiple purposes and not only as a payment instrument. A big amount of the gold in use today is being carried around by people as jewellery. There is gold even in the device you are reading this text from.
Furthermore, investing in gold can be a hedging tool against crises. This is because gold price moves differently than, for example, bonds or stocks.