I'm going to say it probably breaks down to age groups from my experience.
Over 55 - 30-06
35-55 - .270
under 35 - 6.5 Creedmoore
I really don’t think so.lol. This could be very true.
If anybody wants not to read the following, then I’ll boil it down: the cited 55+ year old isn’t as old as you think.
Consider that that 55-year-old wasn’t born until 1968. By their birth, even the “new” .270 Winchester was already well older than their parents: it had been 43 years since its introduction as a factory chambering. Jack O’Connor--arguably a greater force for the .270’s success than was Winchester theyselfs—retired from Outdoor life before that 55 year old’s 5th birthday, then died (and stopped writing) before most of them were 10.
The .30-06 was already old by that point, and was no longer the US Military Complex’ round of choice: the M14 was adopted in 1957, and even it had already been supplanted by the 5.56x45-chambered M16 4 years before the 55-year old was born. .30-06 continued with some non-hunting loyalty for several years, but even in competitive circles (people very comfortable with the esoteric), it was basically out of the game by the 1980’s, if not sooner.
I mention all that history of the .30-06 as a reference that your average Gen X shooter (1965-1982/3) not only never served under an -06 chambered rifle, they also had begun to see some downturn in its perception as a cutting-edge cartridge, and saw a known-reduction in the availability of cheap military surplus ball ammo.
It was, by the time they were of any buying power, “the shell in grandpa’s old rifle”.
Meanwhile, faster and flatter (and simply more numerous) options like the (.244)/6mm Rem (1955), .243 Winchester (1955), .308 Winchester (1952-ish), .300 Win Mag (1963), 7mm Remington Mag (1962), 7mm-08 Remington (1980), were cutting edge, and coming into their own in market share and gun-tabloid articles during the formative years of your Gen X kids.
The debate over whether any of the above can kill deer deader than a .30-06 or .270—or any other relatively fast, small-to-medium bore cartridge, from .220 Swift through .375 H&H—is a worthwhile use of time only if you enjoy arguing over the subjective.
My point is not that the hunting community always tried to be at the cutting edge—if they did, the .30-30 would have died in 1906—but that we can and are influenced into trying new things, even if it’s years later than other shooting groups perceived and/or realized the benefits of a new approach.
By now, the Gen X hunter has "seen some sh**", and has probably been inundated with information long enough that they have at least fired--if not hunted with--something more modern than .30-06.
My opinion as a die-hard steel plate .30-06 fan is that the average deer hunter of the past 30-40 years, with average shooting ability chooses something else, if it is perceived to kill deer as well as .30-06 and .270, but does so in lighter, shorter rifles, without as much recoil and blast.
If you want to see evidence for that, you need go no further than the 6.5 Creedmoor--which as a cartridge, does nothing new--but may become an historic benchmark of successful promotion across nearly all demographics of the rifle-shooting public.