The practical value is reinforcing among the general public the idea that humans should not be able to move freely around their own planet. In the future only money will have that right. The modern passport didn't even exist until World War Ⅰ: https://www.amazon.com/dp/0521634938 / https://archive.org/details/pdfy-S0NQwPjPkMlzZ2eS/mode/2up