... "Concorde which was 8 years from flight to service entry."
Slightly less than seven years, actually.... March 2, 1969 to January 21, 1976.
Not quite comparable... two early prototypes were built and used to prove that the basic concept of a Mach 2 airliner was even viable.
Mach 0.8 airliners have been around for how many years?
Admittedly, even on Concorde, the coffee makers have remained a pain to the bitter end.
CJ