Solo mining has the same expected income that pool mining over a long-enough time period. Obviously, if you have little hash power, the long-enough time period might be decades or centuries, effectively making your hash power a donation since you will never see a reward. But still, there is a chance and, when looking at the limit, reward should match pool mining.
On the other hand, zero fee routing is guaranteed to give you no income, no matter what.
It's different, isn't it?
Solo mining has the same expected income that pool mining over a long-enough time period. Obviously, if you have little hash power, the long-enough time period might be decades or centuries, effectively making your hash power a donation since you will never see a reward. But still, there is a chance and, when looking at the limit, reward should match pool mining.
On the other hand, zero fee routing is guaranteed to give you no income, no matter what.