If you're poor and have never driven, have no driver's license, don't travel abroad, don't have a government job or whatever else with an ID... well that school ID is only good for 2 years after, and as you get older and have nothing else, you get nothing else.
If you're homeless, lost everything in a fire, have lovely family that hid your ID, etc, even getting a replacement for your Social Security card can be mission impossible.
Here in New York, you need 6 points worth of different types of identification (some are each worth more points than others) to get a driver's license. And if you don't have that, but need ID, people say well just get a State ID instead. But you need 6 points to get that too.
I've told people, if you're ever going to drive or whatever else, apply before you're 18, so at least you could use your parents as proof of who you are. Because once you're 18, you're on your own, identification wise.
These 3 guys that I know once got pulled over in Yonkers for a busted tail light. Two brothers mixed Hispanic, they looked typical 'White,' but the other dude, born and raised here (Bronx) of Puerto Rican background, well he looked what some might consider typical Mexican. The brothers told me this story, they said they felt really bad because the cops kept calling the 3rd guy "esse" and other things referring to him as Mexican, jeering him like that while they had all three sprawled face down on the street. That was a bit over a decade ago. If that happened today and he didn't have a driver's license or passport in his pocket, in theory he could have gotten shipped out to El Salvador or something. And he's a US citizen.