USB-IF certified is a certification that the cable follows the spec, but that spans usb 2.0-only cables up to USB4v2 cables. The tester shows you what the capabilities are.

Yes, there's even a spec here: https://www.usb.org/sites/default/files/usb_type-c_cable_log...

The cables are supposed to be labelled with their maximum speed (5, 10, 20, 40, or 80 Gbps or nothing if no data) and maximum wattage (60W or 240W).

HOWEVER, I don't remember ever seeing a cable with such a label. I'm sure they exist, but I don't see them. Requiring products to be labelled, and treating mislabelling as fraud, could mostly solve this. It's definitely a real problem.