Strong analysis, and very interesting when comparing to internet adoption (although must be wary of apples/oranges).

The numbers you get for crypto market size are actually very similar to figures I came up with when doing some modelling for internal research.

In a May 2017 study, Cambridge University estimated there were between 2.9 million and 5.8 million users actively using a cryptocurrency wallet. This figure did not include users whose exchange accounts served as their de facto wallet, and admitted that “the total number of active users is likely considerably higher than our estimate of unique active wallet users.”

However, if you assume a trend between Market Cap and Number of Users, then the current amount of ‘users’ in the cryptocurrency market is around 30 million.