We live in an abundant world...
It all depends on what is meant by poor.
Few people in America must go to bed hungry and cold in the 21st century, so far, yet that has more to do with technological advances than opportunity. Most houses, prior to 1970, were not well insulated and the windows were single pane. Now when one goes inside a modern building, he/she is better protected from the harsh elements. Food technology has progressed as well.
However, compare opportunity to succeed today to those of 1900. Early last century, entrepreneurs and innovators could discover/invent/produce and move up in society due to diligent perseverance. Today, established businesses are protected from competition by high start-up costs of business license, professional license, insurance, government regulations, and on and on. It is simply too burdensome to start a business today unless you are well connected to the elite.
While most poor in America today are not starving, in real terms only the very wealthy are doing better today than 100 years ago.