> It's about the same.

It's absolutely not the same. If I go to a WebUSB page to make my device work, it won't magically have access to all my private files and be able to upload them god knows where or to destroy them. Or access to my entire LAN. Or access to my other peripherals.

Any local driver/software will be able to. (Yes I am familiar with sandboxing technologies, they still aren't the default way to distribute apps outside of iOS/Android).