It is tricky to get someone to recognise that they aren’t knowlegable enough. Even if you say it as gently as possible, some will still hear “you’re dumb” and no one likes that.
Also it’s a great tool to manipulate people : “I don’t need a scientist trying to explain me life from the depths of their lab !! I have commonsense !!”
I have yet to notice anythig different about the time to pour soy sauce in a dish. In any case, soy sauce first, then salt.
Unless you happen to have made a soup that taste bland (we all make mistakes), then a dash of soy sauce can help.