But if it's an unconditional guaranteed income, i.e. each member of the family is making it, then it shouldn't be a problem. For example, a single mother with two kids would get her 500 EUR/month plus 500 EUR/month for each kid, bringing in a total of 1500/month for the family. While this certainly isn't massive, with a part-time job and being frugal, it should enable her to pay the bills.
Also, you don't have to live in the most expensive part of the most expensive city... Good livable apartments can be had for 300e-400e/month, even in the larger cities.
But if it's an unconditional guaranteed income, i.e. each member of the family is making it, then it shouldn't be a problem. For example, a single mother with two kids would get her 500 EUR/month plus 500 EUR/month for each kid, bringing in a total of 1500/month for the family. While this certainly isn't massive, with a part-time job and being frugal, it should enable her to pay the bills.