We are still waiting for the results of the current census. Where did you get the 44% figure from?
The 44% figure comes from the Greater London Authority, but should be clarified a bit. There is a BBC article[0] about this which states "... 44% of the city's people are now of black or ethnic minority origins".
I don't know if London demographics are the point of comparison, e.g. if you looked at FAANG's demographics you would not compare them to the Bay Area as their hiring pool is much wider than people who grew up locally.
As someone who used to live in London, I assure you it's not.