In some instances, yes, power has been drastically increased and mpg has remained similar. Exampl: C4 Vette of the mid '80s vs. C6 Z06 today
However, my point was more directed to standard everyday vehicles like my SHO. Todays cars aren’t that far ahead in the mpg category, despite advances in technology. I’m just surprised that some of the high tech engines out there don’t deliver a little bit better.