With better BC bullets the 308 closes the gap a bit. But the faster 6.5's will always have the advantage when it comes to longer ranges. Everybody wants to run ballistic numbers using a .400 BC 308 bullet. Yeah, it has horrible ballistics with that bullet. Handloads give the 308 much better performance than some crap factory remington hunting load. With good handloads the 308 can hang out to as far as 600 yards. Thats "pretty" far. Run out to 600 yards on foot and tell me how short range it is. But past that, it starts losing to the 6.5's. Its all in what YOU want in a rifle. Not everybody needs or wants a 1k yard steel plinker. Nor does everybody compete in PRS. Surprise surprise? Not really.
Shoot either out to 600 with good handloads (and most factoy match ammo) and tell me how much difference there is. Its minimal. And some would argue as far out as 700-800 yards. Thats pretty far. Certainly most "normal" hunting conditions rarely exceed those distances.
Again, its all in what YOU want in a rifle. I personally love all the ammo choices a 308 has to offer in a pinch. And my favorite 6.5 (a 6.5-284 Norma) has very little.
Edit: This is like saying nobody needs an 18" barrel. Because WHY would you want an 18" barrel when you can get better ballistics from a 26"? Its easy. I want an 18" for convenience. And I dont personally NEED a 26" for hunting and steel.
Stupid video.