The problem in general seems to be that there’s no way to have meaningful choices with cool abilities since elements of the community will immediately min-max all the flavor out of it, declare X the optimal choice for Y content and then at the highest level everyone uses X. The wannabes who imitate the highest level see everyone using X and then also start using X exclusively and ostracize anyone not using X. Then the middle-tier elements of the game see the top tier and the tryhards using X and also demand X, and since this tier is often the most toxic, selfish and rudest of the bunch they outright insult anyone who doesn’t use X.
You see where this goes, because it’s gone that way for almost everything else, whether it matters or not. Eventually the perception becomes that X good, everything else bad, anyone not using X is a baddie/scrub and should be kicked/declined for not picking X.
This is not how any sort of game, let alone an RPG, should function. But there’s no easy way to fix it without stripping abilities of anything that makes them interesting, which would make them a superfluous choice and probably get a lot of “why even bother” sort of remarks if it doesn’t have a tangible benefit. If the covenant was just a neat world power and cosmetics/non-tangible benefits it would satisfy the RP aspect but not the gameplay aspect. Making it too tangible satisfies the gameplay aspect and kills the RP aspect because people are going to pick the best effect irrespective of the RP part in many cases because they don’t want to be shunned from content for picking RP > Gameplay.
The double-edged sword here is that you have a game which wants meaningful abilities and wants to inject flavor and choice, and a player base which has (de)evolved into not caring about anything but the best choice for any piece of content. Being “good enough” is no longer the baseline, it’s “best or nothing”.