The problem is bigger than what people are discussing.
DS4 uses wireless for transmitting inputs, NO MATTER WHAT. Remove the battery, connect through wired, it doesn’t matter. The DS4 is not capable of transmitting controller input through USB. If the PCB has power, it will send all controller inputs through the wireless radio.
I know this because I had a stick modded last year and it kept dropping inputs and lagging out, because the (battery removed!) DS4 PCB was trying to communicate wirelessly with the PS4 from inside of a metal stick case. I had to have the stick re-modded and replaced with a Hori FC4 board, because those pads send input signals through USB.
The reader may be inclined to make some retort about my one-off problems with one sketchy stick. To you, I say: I had problems with dropped signal with ONE DS4 PCB communicating with ONE PS4. Now put DOZENS of PS4s in one ballroom, and have them try to sort wireless signals from the other DOZENS of DS4s… all communicating wirelessly at the same time.
This will not end well.
edit: Just wanted to point out that this post is referring to connecting a DS4 to a PS4; DS4 can send inputs over USB when connected to a PC.