Thank you for your analysis.

I don't think it's a numbers issue. Japan with 127 million has multi-provider solutions such as IC cards, and I've heard India has Aadhaar and China has similar services.

But I agree with the federal part. I guess it makes things harder as federal states of Europe (Germany, Switzerland, Spain) has some centralization and bureaucracy issues, but at least they still manage to get a national systems such as ID cards.