It's not so much to do with how much "flavour" a circuit has, as what
sort of circuit it is. In the end, Silverstone was transformed into something other than its original design. Which had to be done if was to survive over the years.
Other circuits in this thread didn't really change much, if at all, and were killed off in the process, a bit evolutionary really. They couldn't adapt to the changing standards of the sport.
Fortunately, weirdoes like me (
) can drive the older, simple and flowing circuits without fear of danger in racing simulators. Shift 2 was brilliant for bringing these older layouts to the consoles, for more people to discover them. 👍