seconding NR's welcome, so hello greenman, it'd be a good idea to make an introduction thread so we can "officially" say hello!
but yes as paul highlights salt is an invaluable part of our diet, its one of the things contained in these electrolyte energy drinks, to make them better at hydrating you, its all to do with water potential, e.g. the difference in concentration of water from one area to another.
so imagine 2 liquids eitherr side of a water permeable membrane, one is pure water, one is full of dissolved minerals and salts (i say salts because although traditional table salt is sodium chloride, there are manny other types of natural salts as a salt (in chemistry) is simply defined as ionic compounds that are made when an acid is neutralised with an alkali (base) and as you can imagine this definition expands to alot of different natural materials, but sodium chloride is the main one. anyway back to the point at hand, solute full water one side, pure water the other, rather than the water being pulled through to dilute the side with less pure water the dissolved solutes will move toward the side with pure water, so rather than hydrating you, it would just suck out nutrients, but if the water is balanced with added minerals and other solutes then you'll have more water moving toward the other side (also the size of the holes in the membrane contributes to what goes through it!)
According to the CDC, the average intake of sodium for American adults is about 3300 mg of sodium a day which is a ridiculous amount seeing as the guideline from the usda is 2300mg and from the american heart association it is 1500! (yeah i know american guidelines but was going for a quick google search to illustrate the point + americans are the worst lol) but heres the kicker, the average hunter gatherers intake of salt was roughly a mere 750mg a day, half of the lowest recommendation!
so simply by eating berries and meat you will easily meet the amount of salt you need, and as we've barely evolved since the times of hunter gatherers in terms of nutritional intake and digestion there is no need to add salt to your daily diets, we already operate at 5 times the amount we should eat! and even eating responsibly and watching salt intake you could be eating double or triple what you should
anyway if anyone wants to know more just ask, i can go into the various roles that sodium chloride and sodium ions and chloride ions have in the body and why they are so important