It's not hard, really, given that you will need to make only $1.90 per day to automatically become declassified as poor [1]. If anything, capitalism makes this harder to do achieve [2] which probably explains why the limit is set so low.

[1] https://www.investopedia.com/terms/i/international-poverty-l...

[2] https://www.sciencedirect.com/science/article/pii/S0305750X2...