Why do the younger members of the us underestimate the importance of the U.K....?

Okay so how can the U.K not be seen as powerfull .. The U.K is the 6th largest Economy and considered generally as the 5th best military and also has great cultural influence (especially in Asia) so my question to you (younger) americans is how is the uk not powerful? I expect to get a lot of silly answers like "the U.K is a turd" but look at **** wholes like slovenia,slovakia,poland,mexico,thailand… etc;