Why does it seem that there are so few actors of South Asian origin in Britain?

I've always assumed theatre actors come from privileged backgrounds, certainly not many working class getting into theatre acting. So the same could be about working class white British. As for south Asians, vast majority of British Pakistani and Bengalis come from working class backgrounds. The more middle class British Indians (Punjabi Sikhs & Gujarati Hindus) are more likely push their children academically rather than theatre/music. Also you're one of the lucky ones to make it to west end, alot of theatre/acting work is not as glamorous. British South Asian culture (Indian culture especially) put a high importance on a good high earning and respectable progression (doctor, lawyers etc) rather than someone who plays small roles in plays.