I try to encourage folks making statements such as this to reexamine the circumstances under which this assertion is made.
For 50 years or maybe a tad more, every model hunting rifle sold in the US was chambered for the .30-06 Springfield. So it stands to reason that it's still one of the most popular, there are millions of rifles needing to fed every year. The runner up would probably be the .270 Win.
I'm not quite sure where it sits on the list of long range hunting cartridges since I'm not sure there is such a thing. But in my own humble opinion, it is probably an 'also ran' cartridge in the long range hunting venue, not high on the list and closer to the bottom than the top. This doesn't mean that it can't function in the same field as other more notable and popular LR cartridges. When loaded with an aerodynamic, wind cheating bullet design, the .30-06 is perfectly capable of dispatching game at longer distances as long as we pay attention to the basic rules of hunting wild game.
Regards.