Claude Shannon. Maybe rms.
Its not that we don't have genius anymore; we simply built a new pantheon out of the geniuses of the day about 150 years ago and then haven't been keeping up with the work of canonizing new members.
Dale Carnegie and Elon Musk get the "demi-god" status, somehow; we know their successes are the work of many others but who but the most obsessed know those names?