if you want to get a bunch of rifles do not buy a 308 or 30-06 first.
Change the words from "almost the same thing the 30/06 did" to "the same thing the 30/06 does" then you could make a case it might be the most versatile. You can load ur 06 down to 308 but u ain't loading ur 308 up to 06 and staying under pressure.
the 308 does what 30-06 did in WWII
actually a little more with 2020s ammo
current 308 150gr ammo is box velocity of 2820fps
current 150gr 30-06 ammo is 2910fps with the same bullet
yes you can load 30-06 higher now but in factory offerings they are not that far apart.
Win power points
a 180gr bullet out of a 308 is 2620
a 180gr bullet out of a 30-06 2700
really 80fps is not a big deal we use the same .382bc 180gr power point in 308 and run the numbers
30-06 with a 200 yard zero is 1.9 inches high at 100 yards , and 3.4 inches low at 250yards
308 with a 200 yard zero is 2.1 inches high at 100 yards and 3.7 inches low at 250
the only thing in the calculation changed was muzzle velocity
no animal is going to know the difference in a bullet width difference on any good shot at 250 yards
since those are average velocities it is entirely possible that your slow 30-06 round and your fast 308 round are going within a few feet per second of each other
in a bolt action rifle they are really really close , but a good argument for more versatile is that the 308 fits in so many platforms
AR-10 , SFAR. lever guns , pumps , single shots , bolts a lot more offerings in 308 than 30-06
and you can cut some weight and length of your gun , as well as a little weight in the ammo , not a lot but when you pay by the ounce for light weight equipment.
if your going to pay big money to shave ounces on your back pack , your boots , your sleeping bag , why not give up 80fps to save weight on your rifle. if it only costs you 1/3 of an inch at 250 yards.