I wasted so much time trying to develop an accurate load for my 30-06 rifles, only to discover the inaccuracy problem was the rifles, themselves. Live and learn!
Even so, I've always wanted an accurate 30-06 rifle but never got one. Instead, I got a Remington 40-X in 308. Everything I learned pursuing 30-06 transferred over to my 308 loads, except the 210 bullets which were just too heavy for 308.
Certainly, I got accurate 308 loads but they were developed for a known-good rifle. That rifle/cartridge combo is good out 1,000 yards and beyond. It was the rifle, not the reloads, that were the most important change from my days loading 30-06.
These days, I see no reason to go after 30-06 unless, perhaps, you are after terminal ballistics (hunting). You can do almost everything else with a 6mm or even a 223 at lower cost and with less shooter punishment. If you already have the 30-06 and don't want to buy a new rifle & cartridge, well, okay.
If you disagree, please, let me know where you feel a 30-06 fits in.