Sure, dot-com valuations were high in 2000... but smart people were getting concerned about dot-com valuations as far back as the mid-1990's. Alan Greenspan, head of the Fed, was publicly raising concerns about "irrational exuberance" in 1996. And yet, valuations kept getting sillier for another half a decade. Why did the bubble end in 2000? Why not earlier, or later? Why was it a crash, instead of a slow decline? Why did everything suddenly change, seemingly all at once? There's no consensus on the causes of those sudden market movements.
Otherwise, I agree there quite a few parallels with the present.
Otherwise, I agree there quite a few parallels with the present.