What does Fukuoka have more than Osaka? What could make me choose to go to one city rather than the other?

I will be visiting a lot of cities in Japan this summer but I've recently found out about Fukuoka, it looks really beautiful and it's near some beautiful beaches too.

I had planned to finish my trip with 5-6 days in Osaka but now I cannot decide between the two cities, I wouldn't mind checking a less mainstream option (and visit those nice beaches since I won't see the sea this year).

I will also visit either Hiroshima or Nagasaki so I can make a daytrip from Fukuoka if it's the option I choose.