Hey @rufusfirefly, that's a great point, thanks!
There is definitely a break between 0.000 and 0.015 due to the "minimum payout" threshold, under which posts which have an expected payout of less than 0.02 (so 0.015 after curation) do not actually pay out to users.
So you are right, there are a very large number of users who earn 0.000 - due to no votes received or insufficient votes to reach 0.02 payout on any post (I only include users in the author earnings distribution who make at least one post or comment).
Building an actual model of the earnings distribution would probably require looking at the distribution of the underlying reward shares (i.e. the raw vote amounts allocated to posts) with a conversion function to earnings payouts.
That underlying distribution will also most likely need separate processes between users that receive 0 votes/reward-shares and the remaining distribution.