I don't see how this is a "weird asian supremacy replacement theory" when Britain wholesale welcomes these changes as a part of their future, many Western countries welcome immigrants for a) brain drain from other countries and b) so their economies maintain growth. Nothing supremacist in that and nothing I said implies anything about supremacy or Asians beyond the fact I myself have Asian heritage.
I mean, when any high profile white person does complain that they don't want this, they are called a replacement theory conspiracist nazi. And they are basically cancelled from mainstream media.
But to be fair, you are right in a way, I personally believe the UK is the most welcoming non racist nation on earth. I'm saying that as someone who's experienced it firsthand.