If you're worried about that, you can just disable WebUSB in the chrome settings. Any website will be denied access to that API from now on. And what's even better: you can selectively enable WebUSB for some websites.

That's what I do and that's what I suggest for any security-conscious user to do. Just explore Chromium settings, there are dozens of various APIs that could be disabled. Do you need Web MIDI? I don't. Disable.

Won't work as a default setting for average user for sure, but if you consider yourself an advanced user, do that.