It's a very USA specific thing and people in other countries are often surprised this is such a big deal, because in many countries it's a non-issue. Mostly because having an ID is so ubiquitous in many places. People are often surprised that many Americans don't possess ID.

There's a lot of stuff about the US elections that's surprising to e.g. Europeans. Why do so many not have ID? Why do you so often have to wait in line for hours? Why do some areas apparently have not enough polling places? Why do I need to register to vote, sometimes repeatedly? Why is it so hard to get time off work to go vote? A lot of these seem like basic requirements for a functioning democracy.

The US election system has a bunch of historical quirks. And also to my eyes there seems to be a conscious effort from some government officials to make people not go vote.