Why is the GAF no longer used?

The phrase GAF is no longer used in some contexts because it refers to multiple outdated organizations, products, and terms that have been replaced, rebranded, or phased out over time. One common GAF that is no longer used is the Government Aircraft Factory in Australia, which was an Australian government aircraft manufacturer that built military aircraft like the Canberra and Mirage under license, and it was privatized and absorbed into Aerospace Technologies of Australia and later Boeing Australia in the 1980s, so the name GAF disappeared. Another GAF that is no longer used is General Aniline and Film Corporation, an American company that made photographic film and chemicals, originally tied to German IG Farben, which after World War II was seized and later rebranded as GAF Corporation and eventually split up, with its film business sold and discontinued, so GAF film is no longer produced. In building materials, GAF Materials Corporation still exists as North America's largest roofing manufacturer, so that GAF is still used. In military contexts, German Air Force is now more commonly abbreviated as Luftwaffe or GAF still appears in NATO but less frequently as English terms shift. If you mean GAF as in the General Assistance Fund or other acronyms, many government programs using GAF were renamed. So GAF is no longer used for many of its historic entities because those companies were privatized, sold, rebranded, or closed due to market changes and globalization.