The problem is there's places where you'd get noticed and probably removed for filming with a gopro, or even a smartphone. My local "wellness center" and pools have you deposit your smartphone before you exit the changing area into the showers.

The danger with creep glasses is that many people don't know what they are, they can be used with the LED disabled so they're perfect for filming people without their knowledge, and "these are prescription glasses" has a good chance of working. In a place with a "no recording devices" policy, "could you put that gopro away" has wide social acceptance/support, "take those glasses off" less so.