You don't have to be a superpower to be a prosperous society. This loss of superpower status means you need to refocus your efforts on the tractable instead of wallowing in has-been fantasy.
The scary thing about 21st century Britain is the extent to which they now wallow in the never-happened fantasy of the Harry Potter universe to compensate for it. That has changed absolutely everything, not all bad to be sure.
Of course that is true but it undeniably helps. I wonder if postwar Britain watching its hegemony decline will be anything like the current decline of the US.
