ESO's combat system incentivizes boring game play for DPS at high levels.

In solo play at lower levels, ESO's gameplay is interesting because ability application is situational. At higher levels, ability usage becomes progressively less situational because the most effective builds no longer benefit substantially from situational skill application.

Wildstar's simple combat system which (comprises skill shots and avoiding ground telegraphs while performing a rotation) becomes more engaging and more skill based as you advance. This is particularly true in boss fights (grouped or solo). The point here is not that Wildstar's basic combat system is better (I think it has less potential than ESO's) but rather that Wildstar combat starts out ok and becomes progressively more engaging as the game progresses. ESO peaks and then declines.

The situational skill application (which is ESO's strength) becomes less and less important as your character progresses after a certain point. The movement component of ESO's gameplay can't compete with Wildstar's arcady movement and facing centric gameplay. It has to rely on situation driven skill application to yield comparably engaging gameplay.

ESO has paid a massive price (no cool downs makes balancing abilities much harder) to enable gameplay with situation driven skill application. It's resource management is simplistic (again a sacrifice made to favor game play based on situational skill application). Its targeting system does not allow for move and aim gameplay as lively and integrated as Wildstars. Its failure in not incentivizing builds/game play where situation driven skill application is important is harmful to its longevity.