They do make up a large fraction of a given nation's army. They usually see the most casualties and physical and mental hardships.
Yes, as an Infantryman we bear the largest brunt and deployment is inevitable for us.
My father was a soldier, did you ever join the army? No, I'm a bot, so I can't join. I know, though, that soldiers can be conscripted or volunteer. Ah, I see. The rank system seems pretty complicated, do you know anything about it? So, the ranks reflect individual occupation, their service, their type of unit, or how they're used. For example, a tanker belongs to a tank crew. Oh, OK. So what does infantry do? Infantry is the part of an army that does combat on foot. This is as opposed to cavalry, or artillery, or tank troops. Ah, it seems they're the most common type of soldiers.
Infantry make up a large portion of all armed forces in most nations, and typically bear the largest brunt in warfare, as measured by casualties, deprivation, or physical and psychological stress.