>touchpad controller

>capacitance dip → interrupt raised

>hid driver report: x 512 · y 288 · button 1 down

>...

>One millisecond in, the click has passed through four pieces of software and nothing has left the laptop.

I'm going to press X to doubt.

There's no way you're getting from "finger touching glass" -> "chrome seeing a click" in one millisecond. Heck, I know for a fact that even the cap touch controller isn't going to be that quick.

I would believe it's closer to 40-50ms, E2E. Even if the captouch was instantaneous, 1ms latency latency is in the realm of RTOS, not a general-purpose OS feeding a bloated app like chrome.