Your logic assumes that most people are so shallow that they would stop working/trying to improve their conditions after they are able to live “comfortably”. There are several wealthy countries that provide this kind of welfare without much population growth or lazy workforce. On the other hand there are counties like Bangladesh that saw rapid growth in population in the 80s even though most people were very very poor - in fact the country’s pouplation growth has demolished now that more people can live comfortably due to increased wealth and access to education.