I think what you and the other commenter are having friction with is that on your first comment declaring that it is "technically required" you did not specify that it was state by state, and the vagueness gave the impression it was a statement applying nationwide.

Now you are showing a link talking about state-by-state legislation, which is a more restricted and nuanced reframing of the original statement. Beyond that, your link seems to show 39 states do allow homemade firearms with no additional state laws, making that the majority. While declaring the rules one way or the other for the whole nation would be incorrect, saying that they are allowed is less incorrect since the majority of states do allow them.