Good designers will improve visual systems, usability, task efficiency, consistency, symbolism, brand perception, and more concrete things with a redesign. If t

Good designers will improve visual systems, usability, task efficiency, consistency, symbolism, brand perception, and more concrete things with a redesign. If they don't, they're artists, not UX designers. FWIW, most redesigns I see in the wild are doing most or some part of these very real improvements. That said, qualitative value is still value. Just because user feedback on the visual quality is vague doesn't mean that broader goals weren't achieved—users don't know how to evaluate visual quality, but it can still impact their behavior and perception. Good user researchers will look at outcomes and downstream impact in other behavior after a redesign, and those are often positively impacted. Even if the result is just "users feel our company is more professional and mature," that could be extremely important for company strategy and may very well have been a limiting factor beforehand.