Focusing on LR ballistics table will only tell you part of the equation. You have to first ask what the task or game is... then see what combo helps you accomplish the goals.
There is always a compromise and the mains ones are cost and recoil. Higher ballistics almost always require higher running costs and in many cases recoil.
Every chambering used in competition is constantly being updated and modified. There is nothing "old" about the 308's used in FTR shooting today. It can be argued, the current FTR 308 is the cutting edge of LR F class shooting.
If you compare FTR and Open scores at larger US and Canadian Matches, the spread between classes is shrinking and FTR shooters have won the overall match.
On the weekend, I shot in Kamloops at a 500m club match. In very gusty twitchy winds, I beat 7 other shooters (3FTR, 5 Open) using everything from the 223, to 6mm to bigger 7mm. Overall score and V count. Does it make the 308 perfect? Nope... but it certainly makes it competitive.
When doing these comparisons you need to consider where the leading edge of any sport is and what the new norms are. Comparing a 1960's 175gr MK 308 load to a 6.5 Magnum obviously favors the smaller cal. What many FTR shooters are now shooting isn't far off standard 300WM ballistics.
That's a huge change in the playing field and what the lowly 308 can do. Sub 1/2 min 308's at 1000yds is the new norm
Also, tracking and predictability. I know the obsession today is with BC and reduced wind drift... easy to see on a computer screen but any set up that tracks properly through the air and is predicatble and repeatable can overcome some very heavy winds.
There are some here that have shot with me LR when I was chasing them with my 223 vs their 338LM's. Even out to 1450yds, I was hitting the same targets. Did I have to hold over more? Of course Did I have to use more elevation on the scope? Yipe.
Did the rock care? Don't think so.
So part of effective LR shooting involves the shooters ability to put that bullet on target. With "enough" ballistics and a good understanding of the air, lower BC sets up can be just as effective.... not as easy but you just have to be better at this game.
Knowing you need 4 mins of wind usually beats someone that hopes 2.5 is enough......
Jerry