The funny thing is that back in the day, we considered FF4 more story-focused than FF5, implying that FF5 has a worse story than its predecessor. It's still true that the main focus in FF4 is the story, but just because FF5 has so much gameplay going on!
I think FF5 is as story-driven as FF4, maybe a bit less serious, but it's where the really nailed gameplay mechanics. Possibly the best throughout the series, if not 16-bit RPGs in general.