The team is a lot better if you have Kemba playing well.
You are basing that judgement on a team that no longer exists from last year. That team had four guys who could create their own offense and could supply 80% of the teams points when they all played. Kemba got to do the one thing he is elite at, which is to operate as a scorer. No point guard required.
This team has two guys who can create their own offense, with Kemba attempting to provide a 3rd and struggling. The remainder of the team must make up for points missed, and the strategy of picking up the crumbs won't cover the increased load, especially since the two most productive offensive role players, Wanamaker and Kanter, are gone.
Anything that worked before is interesting, but mostly irrelevant. The team is different, and Kemba is different. We need ball movement and a passer/creator.
A real point guard, if you will.
The only other alternative is to reconstruct last year's dynamic and find a highly complimentary 4th scorer, someone who adds without subtracting, like Hayward did. Even then, we will never know if peak Kemba would have been able to contribute effectively to a team with him as a 3rd or 4th option instead of him operating as sharing the 1st option.
I doubt he will ever fit the new version of this team, although I hope I'm wrong