If you look at the available statistics on the distribution, you can see that the bots are in the first places. People using bots do not look at the statistics of payments. For the leader, take any of the first wallets and see how they get the blocks. Further all these blocks leave one purse in another and there remain. An honest man who himself unravels captcha, this does not. We all suffer from bots, since they raise the number of captcha from one time to the next. Pools are not working now, but the number of captcha is growing.
 
Now without pools

Distributions
2017-08-31 06:00:03 am
Claims / s 331
Accounts 200

How can now 200 people decide for 1 second 331 captcha   

Previously, when pools were running

Distributions
2017-04-26 10:00:03 pm
Claims / s 60
Accounts 60

Previously, 60 people solved 60 captcha in 1 second