I had an epiphany some years back. I lived in a large city and volunteered in the inner city, so was familiar with issues of poverty, to a point. Then I went to Mexico City.
We flew into the airport and were driven to our hotel in the downtown. It was like most other really big cities, and I saw some people living on the streets, but the overall impression was not bad. Then we hired a driver and car to take us to some sites outside of the city. As we drove and drove, we passed through "zones", some middle class neighborhoods, but mostly a stretch of poverty and slums. For miles and miles it extended. Millions of people, crammed into areas without basic amenities. Seemingly with little hope of ever getting out. I was stunned and discouraged. If I had flown in and toured just the popular sites within Mexico City, I would never have seen this. I was thinking about how many people did just that, and didn't know they were surrounded by a ring of millions of people living in squalor.
Everything was just fine until I opened my eyes.
I know someone who went to one of the poorest countries in the world, in Africa, to serve as a volunteer doctor there. Malnutrition and disease was rampant. The "hospital" of sorts was for the rural population and was located away from the city, was accessible only be dirt roads which were impassable part of the year, with one full time doctor, some locally trained nurses, electricity some of the time, one phone line for the whole "hospital", inadequate medicines and supplies, etc. I heard some very sad stories of people, including many children, that could have easily been made healthy in many parts of the world, but who were doomed to suffer and die for lack of resources.
This goes on in many places every day.
Pope Francis, and Bernie Sanders, are right. But being right in itself will not change anything...unfortunately.