Most high-end burr grinders have settings that allow you to adjust how much coffee comes out for a single dose. The machines also can be tuned to deliver a specific output for a given grind and dose. Given this, it's likely that the barista is still weighing inputs and outputs, even if you don't see them use a scale while you're there.

That's great - you're correct in realizing some of these things aren't really suitable for a "production" env, versus (e.g.) a home enthusiast, which might essentially be a lab environment. There's space for both of them.

I would hope so when they're using espresso machines worth $10k+ more than mine