If literally everybody takes a certain edge then that edge isn't the cause of the mechanical advantage delta between "haves" and "have nots". Because we stipulated that everybody takes that edge.

What creates a game-play delta between the "haves" and "have nots" is that in addition to that certain edge (which both groups take) the "haves" have enough points to take a bunch of other edges as well.

One other thought:

One way to look at edges that are "must haves" but carry a minimum imm xp requirement is that they're empowerment for non-empowerment classes. Devious Versatility comes to mind.