You can't compare the two situations. Post-WW2, the UK 'handed over the baton' of superpower status to a relatively friendly ally. The UK's prime minister at the time was half-American. The dollar was already the world's reserve currency, and had been for several decades.

The US has no incentive to give up superpower status, unlike the UK post-WW2. Why would the UK spend billions to protect shipping routes where transactions were mostly carried out in dollars, for example? Also bear in mind that a fair chunk of the UK's power came from people who did not consider themselves British, and in many cases did not want their country to be run by us. Why would we, or they, want us to spend money to keep them as part of the Empire? (By 'us' I'm referring to the British people as opposed to some of the wealthy businessmen who profited greatly from the Empire)

None of these factors exist for the USA in 2021.

Actual brainworms. Love to live in a world where superpowers voluntarily give their power away to rival empires, especially ones which you've gone to war with over their independence lmfao