The issue is Type 4 body armor that can stop 5.56x45mm and other intermediate cartridge rifles. The 5.56 was good enough when body armor was not widely available. Now that everyone wears kevlar and plate carriers, the 5.56 simply does not hit hard enough for the threats the army now faces.
I’ve been in the market for another carrier.
Even the Level 3 Stuff I am looking at is rated to stop 5.56.