Such barriers should be rectified before making ID mandatory. If the response to that is "well then we'll never be able to implement this!" then one should have a period of deep reflection on why that is and its implications.
When it comes to creating systems whose consequences infringe on rights things like "the vast majority" aren't valid escape hatches. This is doubly true when the folks making the rules have political motivation for disenfranchising the very same group who doesn't have IDs in this case. In fact, when such discrepancies are pointed out and then are instituted anyways, such biases functionally become the point of the institution and increases culpability rather than decreases it.
When it comes to creating systems whose consequences infringe on rights things like "the vast majority" aren't valid escape hatches. This is doubly true when the folks making the rules have political motivation for disenfranchising the very same group who doesn't have IDs in this case. In fact, when such discrepancies are pointed out and then are instituted anyways, such biases functionally become the point of the institution and increases culpability rather than decreases it.