“But these gains were notably less than for playing tennis, which was linked to 9.7 added years of life”
Cycling and running are essentially individual exercises (yes there are clubs but the activity is solo).
Tennis requires at least 1 other person to play.
I would imagine that the social aspect of tennis adds the extra boost, plus it’s not quite as intense as those others - breaks to change ends and between serves. So more of an intermittent exercise.