One of the major problems of ranger is that the popular TWF style doesn't work well with other ranger features because of its dependence on bonus actions.
So along comes Favored Foe that doesn't require a bonus action. Yay, right? Wrong. Unfortunately it only applies to a single attack, making it no more useful for a TWF ranger than anyone else.
Ranger probably needs a class feature to allow them to do something like cast a bonus action ranger spell while also making a TWF attack or something, like the orc needs a racial feature allowing them to initiate barbarian rage when they use Aggressive. Both are situations where the game basically punishes you for playing to type.
No, what we need is for the additional attack from TWF to be part of your Action, not a bonus action. It will ruin exactly nothing about the game to do this.