I was curious if this was still the case and upon doing some research it seems that the stats regarding the “largest” Navies and Air Forces have changed in recent years. According to the Wikipedia page on US armed forces, it seems that the largest Air Force in the world is still the US Air Force, followed by the US Army Aviation Branch. The US Navy has fallen to the fourth largest Air Force in the world, while continuing to be the largest naval Air Force in the world.
Regarding Navy sizes, it seems that the US Navy has dropped to the fourth largest Navy in the world behind China, Russia, and North Korea (this one was rather surprising to me).
That said, the world’s two largest Air Forces still apparently belong to the US military. Furthermore, size does not necessarily equal power. Countries could inflate their numbers, or even presumably count vessels that aren’t what we would consider military vessels; e.g. pad their naval numbers by counting unrelated fishing boats as part of a Navy. When you factor in technology, training, and modernization of “old” equipment, it seems agreed that each branch of the US military is still the most powerful in the world compared to other countries respective military branches. And judging by the fact that the US military still has three (!!!) of the top 5 largest Air Forces in the world, as well as having each respective branch of its military in the world’s top 10 largest, I would hazard a guess that the power gap is quite large.