Putin may well be bluffing. During World War II and the Cold War, American technology was decades ahead of the Soviets. The USSR military and civilian sectors relied on technology bought or stolen from the West. (Refer to Antony Sutton's books from the 1970s.) However, do we still have the edge in technology after 30 years of military decline? The younger Bush spent a lot of money on Middle East wars. Clinton, Obama, and Biden were/are more concerned with social engineering rather than military strength. Trump was not in office long enough to reverse the decay.
The Russians are not living up to their boasts as evidenced in their Ukrainian invasion. However, it is questionable that the U.S. and NATO military forces would be successful in a confrontation with Russia.