How is frequency related to data rate?
There's simply no inherent relation between carrier frequency and data rate. 

I assume a classical comms engineering education here, but since that most often introduces the concept of equivalent baseband early, a good explanation would be:


  This becomes obvious when you think about the complex baseband representation of a passband being the same, regardless of the passband's center frequency, and that the complex baseband carries identical information to the passband signal.
  
  Thus, carrier frequency cannot have direct influence on the information transport capabilities of any system, given that you mix the same signal to these carriers.


Indirectly, there might be influences: Bandwidth is proportional to capacity; it's impossible to get 1 GHz bandwidth centered around 433 MHz, but cheap around 60 GHz.

Noise and interference are the other limit to capacity; these are different for different bands and technologies.