Starlink offers a faster and much more reliable internet service because the Satellites are in lower orbit and there are more satellites compared to the NBN. There are over 7,000 satellites worldwide and they are constantly moving in low earth orbit! SpaceX launches an average of 60 new satellites a week!
The NBN Satellites are higher in orbit, which means there is a larger distance for communication of your data to and from your dish, resulting in a longer response time (also known as latency). Also, there are fewer (last time we heard, only two satellites!) NBN Satellites, which results in slower internet as every other user has to use the same bandwidth provided.
Upgrading to Starlink can serve you better than NBN Fixed Wireless or Satellite!