If your income goes up 800€ and your taxes go up 800€ then your disposable income does not increase. For those near the poverty line who will pay less than 800

If your income goes up 800€ and your taxes go up 800€ then your disposable income does not increase. For those near the poverty line who will pay less than 800€ in new taxes still need to eat, so they cannot pay 800€ more in rent.