The phrase "bottom of the pyramid" refers to the largest and poorest socioeconomic group in society. It represents the people who have limited income and access to resources. Full definition
They represent a true leapfrog technology that directly enhances the lives of those at the so - called bottom of the pyramid. (epolitics.com)
We need an open access to all entities desiring to serve the mass middle and bottom of the pyramid without restricting operations through the banking channel (business-standard.com)
Before kneeling down at the bottom of a pyramid of cheerleaders, Harry impressively threw a few passes of a football. (businessinsider.com)