All of the houses that have sold in my immediate area have had teams of Indian builders swoop in within days of the for sale sign switching to sold.
I don't believe many have sold to actual families, or none that I have noticed have.
Purely anecdotal, but it seems to me houses are selling quickly, but to this particular type of 'property developer'.
I have counted 7 of these sales to 'property developers' in the past 6 months within a few roads of where I live. Most end up with grey framed double glazing, white/beige rendered outer walls, a printed driveway, grey carpets and white walls throughout.