It may surprise you to know that SpaceX is their own best customer… Starlink has consumed over 56% of SpaceX’s Falcon 9 launches since the first Starlink mission on 5/24/2019.
Additional information for the curious
Starting from the first Starlink mission on 5/24/2019 up until 11/12/2022 there have been 115 Falcon 9 launches – of which 65 launches have been Starlink missions. Note that the 65 launches do not include any Transporter missions.
Source data (based on elonx website) is provided below.