In short, the relatively benign state of the island today is a rebuttal to those anti-colonialists who universally condemn the British Empire.
The emergence from the British Empire or Commonwealth should have little practical effect on the everyday lives of the Barbadian people but it does reflect a growing international skepticism toward the Royals.
In many ways I confess I am a Tory Victorian at heart even as I pursue populist principles so I regret the inevitable decline of the House of Windsor brought about by self-inflicted wounds and character defects yet I understand that if the Royals were to abdicate today the Brits would have to run out tomorrow and hire another set for the American tourists.
Just to clarify- Barbados is staying in the Commonwealth. It’s changing its head of state, that’s all. There are other Commonwealth countries which are republics. You don’t have to have the Queen to be a Commonwealth member.