I am using one of the 2020 iPad Pros and a 2017 MacBook Pro. Sidecar works over wi-fi but I notice lag sometimes even if it's plugged in. I was suspicious it was using wifi even with the USB connected and the iPad charging. When I tested this by turning off wifi I was correct and it told me I needed to plug it in or turn on wifi to use sidecar. Why does it not work over USB? Is anyone else having this issue or am I doing something wrong?