https://www.cnet.com/news/qualcomm-vs-the-ftc-everything-you-need-to-know-faq/

Qualcomm is the world's biggest provider of mobile chips, and it created technology that's essential for connecting phones to cellular networks. The company derives a significant portion of its revenue from licensing those inventions to hundreds of device makers, with the fee based on the value of the phone, not the components.

Because Qualcomm owns patents related to the 3G, 4G and 5G networking technology -- as well as other features like software -- all handset makers building a device that connects to cellular networks have to pay it a licensing fee, even if they don't use Qualcomm's chips.