Since private endpoint billing is based on a "capacity unit" that has three dimensions (new connections, active connections, and processed bytes), and the bill is determined by the highest of the three, it is important to know how much of each of these three dimensions is being used in order to make engineering decisions on how to control cost.
For example, if the main driver of usage is processed bytes and the other two dimensions are barely being used at all, then how we would go about how to control this cost would be very different than if all three dimensions are roughly being used equally. Not knowing how the usage breaks down between the three dimensions means there is no real way to plan for engineering efforts to control this cost.