It sounds like you want to say the world needs the U.S. for global trade, but then... obviously the world in a sense needs every country for it to be properly global trade.

No. The US is needed because it prevents any state from restricting global trade in all major waterways.

Saying the U.S. provides security currently, also does not show why some other country couldn't provide it in the U.S.'s absence or decline.

The entire rest of the world's navys combined doesn't amount to half of the US navy

While the U.S. may still have the most powerful Navy, China has the largest at this point, right?

China has almost no navy whatsoever lol

The rest of the post is irrelevant to the statement in the op