What function does the ignore list have? If all it does is automatically mute them, it's kind of a waste of space. If it actually prevents you from queueing with the person you've added, then It would be worthwhile.
Furthermore, does anybody actually use the ingame mute for toxic players? I've only remembered today that it's actually a feature in the game, and I really don't see many situations that players would use it, as it can harm your chances of winning if they happen to relay some actual info later on? (plus it always feels very unmanly to mute someone!).