The alternative is to install random software on your computer for every device (or, if you're a Linux user, you'll likely simply be excluded and whine about it).
Just look at all the old hardware like CNC machines still running just fine on old computers, and imagine if they were connected via WebUSB instead.
WebUSB is just a terrible idea if you're not an ad company.
Not if it's an Open Source project made by a bunch of people for the love of the game. Install a PWA and you have it even when the site is down, if not code available on GH. It's possible to do on a computer (write code and distribute an app not via an app store)...but not in the magical protected-profits land of mobile devices.
Your way of thinking is the reason why we now have a half dozen trillion dollar companies controlling the world.