In Ghana the phone is the primary device, and often a mid range Android on mobile data. A site designed on a large monitor and shrunk to fit is slow, cramped and hard to tap. One designed at 360 pixels wide and expanded reads properly everywhere.
Google also indexes the mobile version of a site first. A site whose mobile version is a cut down afterthought is ranked on the afterthought.
It also decides what gets built: a feature that cannot work on a phone is a feature most visitors will never use.