>>11910369In professional wrestling, championship belts are typically designed and owned by the wrestling promotion rather than by individual wrestlers, including Asuka. The design and use of championship belts are part of the promotion's creative and branding decisions. Wrestlers who hold championship titles, like the NEO Women's Championship (assuming that's the title you're referring to), are essentially "custodians" of those titles while they hold them.
It's not a matter of fairness to the wrestler who may have helped design the belt but rather a matter of how the wrestling promotion wants to represent its championships. Wrestlers often have input into their characters and storylines, but the design and usage of championship belts are under the control of the promotion's management.
If a wrestler has contributed to the design of a championship belt and is proud of it, it can be a point of personal satisfaction. However, wrestlers generally understand that championship titles are a part of the wrestling business, and they can change hands and be used in various storylines over time.