Honestly, and I'm not even a Wayne fan like that, C5 has plenty of substance. That album was basically his 4:44 albeit not as good. It's his only album that's generally full of depth and his perspective on life.
For other Wayne albums, it's true that they're generally just Wayne doing punchline and stream of consciousness rap about p*ssy, money, and drugs. But he did have some occasional songs with substance like Tie My Hands, Grown Man, I Miss My Dawgs, Georgia Bush, etc. Dr. Carter was also a pretty good concept record.
The best thing Wayne can do is make C6 a personalized album like C5 but without the bloated tracklist and better production.