The word salary comes from the word salt. In fact, it was used as a form of payment in many countries. It was also used in bargains. A pinch of salt from the bag worn by each party was added to the bags of the others. Only if those specific grains could be removed could a salt covenant be broken. If it was so important then, why is it being maligned now?
Preservative: Fresh food, particularly animal protein, won’t last without some outside method of preservation. In fact you can see this in the refrigerator sometimes. That dish that got pushed way to the back and turned into a science experiment proves it.
Those in the days before canning had to either dry or salt their food. Salting was easiest… if you lived near someplace that had it. Drying required a lot of work and there was always the chance the meat wouldn’t dry enough or flies would get to it.
Tooth Cleaning: People cleaned their teeth long before toothpaste was invented. Be grateful because salt was often part of the cleaning process.
Goiter Belt: Some areas, including a portion of the U.S. does not contain iodine in the soil. Iodine, in trace amounts, is needed to prevent an enlargement of the thyroid gland in throat area. When this was discovered iodine was added to table salt. As long as people in those areas use iodized salt their chances of developing a goiter is small.
Gargle: How old this practice is I couldn’t tell you, but in most of the herbals I’ve read one of the treatments for a sore throat is a warm salt water gargle. In fact, my doctor has recommended it. It is also used for the sinuses by those can handle the process.
Flavor: Even desserts contain some salt. It’s a flavor enhancer. Without it everything tastes bland. The only way to get enough flavor without salt is to go overboard in the spice department and even that might not work. That is why most prepackaged foods list salt as an ingredient.