Except you aren't locked into a combat ability, you can change it just isn't handed to you...
I guess you've only played one RPG...because that is exactly where it comes from, I haven't played a single RPG that lets you change things willy nilly and you obviously don't have many under your belt if you don't know that,
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Yup...because everyone is a mythic record chaser where every little bit of DPS absolutely matters
If your raid is teetering on a single ability you either aren't that good or your raid isn't that good
Probably both...