I hear what you're saying, but I would push back a bit that the gun purchase vs. voting analogy needs a bit more nuance. There's ALSO a long tradition that individual rights enumerated in the Constitution+Amendments are not absolute, but are limited insofar as they infringe on others' individual rights and public safety.

The threshold where "public safety" is considered with respect to limiting individual rights is certainly up for debate in various cases - including gun ownership. That said, I think there are pretty clear differences between the public safety risk surface of "voting" and "owning a firearm", so I think it's not reasonable to assume that they should require the same standard of restriction (i.e. in the form of tracking/ID requirement).