On what do you base that claim? Some say other periods and places were much more idyllic than our current state.

I had a history class in school? No period sticks out even remotely comparable to modernity by any metric: violent deaths per capita, general life expectancy, education, leisure time available..

If some future historian were to look at the 20th century he would observe a huge amount of violence and death dwarfing anything that came before. I am not certain the modern age is altogether superior.