The only way I see it being easy for pro poker players who depend on playing poker as their only means of income to live without proof of income would be if they live in a country that considers poker winnings as taxable income. Proof of income is needed when you want to rent an apartment, get a loan or even travel in some countries.
This will be a serious challenge for those who play poker as a full time job without a proof of income.
This will be a serious challenge for those who play poker as a full time job without a proof of income.