Oh how right you are!
We buy the finished firearms we like and want because they have been plentiful, relatively affordable and available to us...NOT because those arms are difficult to make or purchase is the only way to legally obtain them...
Firearm manufacture remains a straightforward process, and the quality of end product is dependent only upon materials and machine processes employed, and the ideas and engineering skill of the humans involved...
Now imagine that all goes away, and as individuals and small groups we’re left to our own devices...The mind boggles at the innovation we’ll see when the average handy Joes have a pile of steel, a CNC mill and some novel ideas...