I'm observing a shift to a lot of what I'll call fashion statement designer rifle cartridges..... For example 6.5 Creedmore and 6.5 PRC. I view these in much of the same light as when everyone wanted a 300 blackout... Now you never hear about that cartridge anymore.
Cartridges like the 6.5 are curious to me and I don't get the sudden shift to them. They do not outperform the cartridges they're intended to replace in the hunting world. Mainly the .270, 30-06, and the .308. They're also generally more expensive, harder to find, and underperform on larger game like elk. The higher chamber pressures mean barrels don't last as long. I don't get the appeal.
Over 100 years and the 30-06 still remains one of the most popular hunting cartridges and rifle chamberings... 100 years from now, will we say the same about the 6.5 options or the bastardized 30 cal options stuffed into a 5.56 case? I very much doubt it.
As another stated, 6.5 “manbun” is the one of most popular cartridge for long range precision shooting. Don’t know many who hunt with it, but I’m sure many do.
From what I gather, 6.5 does everything just a bit better than the cartridges you listed.
.30-06 is more versatile and the best all around hunting cartridge in North America, but the recoil is significantly more than 6.5, so it’s not really the go-to for long practice sessions. 6.5 is also a little bit better with wind resistance and ballistic coefficient.
308 and 6.5 are pretty much the same, for the 99% of us. 6.5 is a bit better in terms of ballistics, but there’s no huge difference that the layman will notice.
The true comparison is .270 in terms of ballistics. It’s really similar to 6.5 at distance, and most of us wouldn’t notice a difference. But the recoil is a bit more, and it’s a long action cartridge.
Most people who shoot F class or whatever want a short action, accurate, low recoil round for long range precision. The 6.5 does all of that, and it is just a bit better than .308, .270 and .30-06. All of these cartridges are fine for just about anything you want to do. However, like many things it comes down to gals and dudes buying new tech.
Biggest issue with 6.5 is burning barrels. Alligator skin crackling in the throat and a noticeable loss of accuracy after a few thousand rounds.
Disclaimer: I don’t shoot long range precision. Iron sights until my eyes give out and then maybe I’ll buy a rifle that has more plastic than wood