If the main ingredients were vitamins, that'd massively overdose them on vitamins. For them to not include a lot of salt, they'd either have to make tiny packets, which people probably wouldn't buy, or they'd have to make one packet require a lot more water to dilute it. Note that it doesn't say to give the birds both the vitamin water and clean water, like it does on the other. Plus, that looks like it's intended to be used long-term, not as a quick pick-me-up for ill birds. And, again, the electrolytes are really important.