I agree you can't replace the knowledge you'll be presented in academia, but what good is all that knowledge if you can't effectively communicate with patients and providers? School doesn't teach you customer service, empathy, and how to resolve a problem.
Maybe I'm biased as I dug through the trenches as a tech in retail for two years before starting pharmacy school, but beyond what I mentioned previously my experience with brand/generics, indications, common dosages, and interactions has helped me immensely now.
It's not a replacement to school, but in my opinion work experience is the best supplement before, and during.