The problem is that states have different standards for giving out IDs, so in many areas it is next to impossible to get one if you have no income, or you're a felon (nearly impossible to avoid in some places where people are picked up off the street and charged with drug possession as a standard procedure), or if you have no permanent home, job, former registration in the state system, or other things. It's meant to intentionally disenfranchise democratic voters in the south, but they do the same thing with Republican voters in swing states like PA and Ohio.
It should just tell you that our system is so convoluted and fucked that only a complete overhaul of abolition of the current method will make it fair. That is, if you accept that voting is fair, or that it's real at all. But let's leave that out and assume it is, you can't just have a nationwide voter ID requirement without also reforming the standards for giving out IDs in every state.