[TobTobXX]

If I'be read it correctly it _can_ announce itself over WebUSB. And I suppose this announcement contains a landing URL, which Chrome will then show upon plug-in of the device. So device-side WebUSB capability seems like a feature, rather than a requirement for browser-side communication.

[selfhoster11]

It’s certainly not a requirement for the device to support WebUSB. NetMD recorders were created long before WebUSB, but can still be used from a browser app.