As a Linux user I love WebMIDI, because it means I don't have to open a Windows VM anymore to run firmware updates / utility tools for audio gear manufacturers that embrace it (e.g. Novation).
WebUSB should enable the same for more types of devices, but of course there should be appropriate permission mechanisms.
That is/was a Chrome problem, Firefox only allows WebMIDI after granting permission. Unfortunately its implementation is also incomplete/buggy so I still often end up using Chrome for those use cases anyway.
Webmidi is godsent for Akai LPD8 controllers. It came with software that's used to reprogramming midi banks. Software never got updates and doesnt work anymore in any modern mac. Thank $deity for webmidi and some reverse engineering, i can reprogram it to a degree that its at least functional and dont need to throw it away.
WebUSB should enable the same for more types of devices, but of course there should be appropriate permission mechanisms.