Why did westerners regard salt as a precious thing in ancient Rome?

Salt is the initial seasoning of human food, which has completely changed human eating habits. People will say "no salty taste" when evaluating that a dish has no taste. It can be seen that salt is the most important of the five flavors, and the lack of salt will cause various diseases and even life-threatening. In 65 BC, the ancient people living in Europe had exploited the earliest salt mines found on the European continent. Salt can purify water, preserve meat and fish for a long time, and improve the taste of food. Salt is also a kind of offering by Hebrews, Greeks and Romans in major sacrificial ceremonies. Many westerners regard salt as a precious thing.