Perhaps what has happened this century is that the absolute ruthlessness shown toward civilian populations in the world wars and the number of young men killed (and the propensity of the news media to bring such into our homes) took away the impluse of classical artists to idealize. What you see
in modern artists like Picasso and Francis Bacon is a lot of hatred and self-loathing. For instance Bacon saying that human beings leave a kind of slime, that man is a slug. Then there are the formal implosions of Picasso ...
In terms of material well-being and health, we live better than we ever did but overall there is a staggering pessimism, a staggering nihilism which there has never been in the history of art.
It is this negative aspect 'art' that concerns me and it goes to the philosophy of why we paint and what paintings we should cherish and use to elevate our children's, and our own, sensitivities.