That was more or less my reaction as a kid. About a year ago I found an early 1984 episode online where they don't even do the rigamarole where the category titles dance, it was just "Here's the Tune Topic for today!". Which was better insofar as it got to the point, but it was still a buzzer race without the wheel.
The point of the different rounds is to break up the content. They could alternate Melody Roulette with the Money Volcano for all I care, but that and Bid-a-Note are iconic enough that it would be silly to paste over them.