The government’s R&D efforts were all in the Office of Scientific and Research and Development (OSRD) which was run by Vannevar Bush who reported directly to FDR. Bush notes several times in Pieces of the Action that FDR trusted him on R&D matters and in turn Bush trusted the people under him to give him accurate analyses that he could pass on to the president.
Arguably, this structure was effective for winning WWII. While many things stopped being part of the hierarchy - the government no longer dictated manufacturing plans - the psychological assumption that the government is the default trusted hierarchy remained. I believe this assumption is why the default dichotomy is either government or decentralized systems. But Government centralized coordination versus decentralized efforts is a false dichotomy.