Why is British Standard English superior?

Could you elaborate on the notion that British Standard English is considered superior? I'm curious to understand the rationale behind this perception. Is it due to its historical significance as the language of the British Empire? Or is it the perceived clarity and precision of its grammar and vocabulary? Or perhaps it's the cultural cachet that comes with being associated with a long-standing tradition of literature and academic excellence? I'd like to hear your thoughts on what makes British Standard English stand out and why it's often held in such high esteem.