To play devil's advocate here, though, what qualifies skydiving as an outdoor activity (aside from the very obvious fact that it happens - though briefly - in the outdoors (air))

Yes its a slippery slope, but it seems skydiving particularly leans into the "driving a semi through the wildlands" end of things, being that it is wholly dependent upon an airplane.

Though, para-sailing / hang-gliding might fit...

To play devil's advocate here, though, what qualifies skydiving as an outdoor activity (aside from the very obvious fact that it happens - though briefly - in the outdoors (air))

Yes its a slippery slope, but it seems skydiving particularly leans into the "driving a semi through the wildlands" end of things, being that it is wholly dependent upon an airplane.

Though, para-sailing / hang-gliding might fit...