You have more users/entrepreneurs competing over a reward pool that is fixed.

Minor quibble. The reward pool is not fixed, but it does increase in size very slowly, relative to the number of accounts trying to draw from it. The reward pool gets a little bigger every day because of the Steem inflation rate. But the Steem inflation rate is now under 9% annually while the number of new accounts is increasing by about the same percentage monthly. And that’s before the upcoming fast-onboarding.