Hiking is not considered a sport because it is a recreational, non-competitive activity.
Additionally, the lack of spectators and competitors further 6️⃣ differentiates it from other recognized forms of sport.
The long answer gets a bit more complicated.
While most physical activities fall into 6️⃣ the black-and-white categories of sports vs.
non-sports, hiking is one of the few that lingers in the gray areas in between.