We don’t have a national ID system in the U.S. In Wisconsin they mandated voter ID and promptly closed a lot of places to get said IDs. They made it harder for people to get it. In some states Polling places get closed down in poor areas or make things like 1 drop off location per county regardless of population size. Some places put in enough poll workers to make voting fast while limiting the number of poll workers in less desirable locations to make voting slow.

You can get a passport via mail and can file taxes via mail. Selective Service is done by mail. There isn’t any evidence of voter fraud beyond an extremely small number of cases. There are plenty of sources to give you the information on the ways voter suppression is accomplished. They are easy to find.