They can click everything away, so maybe educate them or buy an ios device for your relatives instead of breaking computing for everyone else.
> breaking computing for everyone else
How is not implementing a Draft spec, which may compromise security badly, breaking computing?
Overreacting much?
> They can click everything away, so maybe
So maybe don't populate the browser with dozens of features requiring permission popups?
Fair, but remember that we are the <~1% of people who even know what webusb is. I'm not sure I share your view on this.
Maybe an about:config switch to enable it would be enough to stop casuals from pwning their peripherals.