I don't know if the idea of a 'national anthem' has any legal force, so it's possible we could all just decide as Billy Connolly does to use the theme from the Archers instead
https://www.youtube.com/watch?v=ZwsUWcK-PzY
The Australians don't have an official one, after all.
Most countries' anthems do reflect the aspirations or the history of the nation in some way. The Ukrainian one begins 'Ukraine is not dead yet', which is a bit feeble; at the other end of the spectrum you've got the gutters running with blood in the Marseillaise. Quite a few mention God, I think, but very few devote the lyrics not to the country but to the monarch.
Anyway, nobody has to sing it. At the start of international matches you can see the players are just muttering 'rhubarb' and the crowd will actually start singing 'Swing low sweet chariot' or chanting 'Barmy army' or something - you seldom hear them burst out with GSTQ, do you?