The real problem that I see with the two "main" titles (WWE title and World title) is that several characters have become "bigger" or "more important" than the championships themselves. Look, we all know that wrestling is scripted BUT the top championship should mean something. It should mean that you are the best or the top guy in the company or you just beat the best to win the title. Nowadays, Cena is bigger than the title. He main events PPVs WITHOUT THE BELT. Same goes for guys not on the regular roster: Rock, Undertaker, Triple H, etc. I'd even argue to some extent, Orton is almost bigger than the belts. This is what has made the championship belts into props. When you have multiple PPVs in a row where your championship matches aren't the main event. I'm not faulting any of the aforementioned guys. It's more so on creative for letting things get out of control and there's also a level of inevitability. Since Cena is the top draw in the company, you don't need to keep the belt on him. Same goes for the others.
As for the midcard belts, the issue is really just the storylines. The belts would be more relevant and important if they were defended regularly and the guys showed they cared about the belt as part of the feud, not just feuding with the other guy. With the IC belt, I think they're starting to get it back to where it's important and relevant but the U.S. title is well... a joke.