There are over 3,000,000 Namecoin domains registered[0], but nobody uses it. Not a worthwhile metric IMO.
Btw, full ENS stats here https://ens.codetract.io
Or simply curious people trying something new. I know I registered a name for fun, and there was quite a bit of curious interest in tech circles in my area (even outside of cryptoanarchists types).
But then, for the moment most people see ICANN regulation as okay. Maybe if that changes, a distributed alternative will get traction.