Why should Apple pay the patent fee to Qualcomm? Isn't Apple's chip its own A? What's the connection with Snapdragon in Qualcomm?

The A-series processor is Apple's, but it doesn't mean that the technology in the whole processor is developed by itself. The network technology used is a patent of Qualcomm. Without the authorization of Qualcomm, your Apple device can't connect to the Internet. Moreover, the core architecture of the processor is based on the instruction of ARM, and you need to pay an authorization fee to ARM.