#1. Becky has no other major opponents to feud with

Overexposure is one of modern wrestling's biggest problems, especially in WWE. The brand split helps with that, but still, it's very easy for fans to get tired of the top wrestlers. Take Becky Lynch on RAW, for example. She has pretty much been the centerpiece of attention for a long time and has gone through almost every woman on the roster.
While that's good to establish her as a star, it can destroy the competitiveness. It feels like she's a step above most of the roster, and they don't stand a chance to defeat her. Now that Charlotte Flair is involved in the tag team title scene, she won't feud with Becky.
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That leaves Asuka as the most believable opponent for Becky on RAW. This feud needs to be competitive and not one-sided as that will do more harm than good. Asuka may not win the title, but she has to take Becky to the limits.