Let's say 9% of all adults don't have a license. They may, as you mentioned, have a passport or a state issued ID, which isn't legal for driving but would be valid for voting.
The reason I mentioned "navigating life" in my original post is because it's very, very difficult to navigate life without an ID. You can't get a job. You can't open a bank account. You can't cash a check. You can't drive. You can't fly. I don't know about all states but,
at least in AZ, you can't sign up for SNAP/welfare without an ID.
So, are the people who are existing in life in this manner, likely to be looking to vote? Do you think they are people who are likely to be in a mental state that they should be permitted to vote?