Surely, "salt" has to be mentioned when talking about the primary taste components of soy? Normal soy is around 17% salt, which is a lot and really plays a part, in my opinion.

Soy sauce is meant to largely replace the salt component of your dish. If you're using so much that it's particularly salty, you're using too much.

Way back in the day, when salt was scarce and expensive, the whole point of stuff like fish sauce, miso, soy sauce, etc... was to provide salt but also cut it by adding other ingredients.