The barrels that high level competitors buy are the ones that are better. If you chamber two barrels a year and wear both of them out, you cant afford to waste time on the manufactures that are not at the top of the game. You or I may never see the difference but there are people that do. You can stand on a soap box all day long and proclaim your opinion, the one I listen too will be the one who has the been there and done that. If I wanted to shoot world record groups, I think I would pay attention to what the guys trying to do the same thing say. Yes lapping/gauging, straightness, chambering etc... matter but in the end group size matters. When you have the ability to shoot small groups at any distance, your equipment will reflect the same. No one brings a Shaw barrel to the top competition regardless of quality of the chambering. But you will see Bartlein, Krieger, Rock, and Hawk Hill maybe Brux near the top every time. I am currious as to why that is..........

There is NO evidence that one type RIFLIN is better. The best is anecdotal evidence.
Button rifling induces considerably more stress than cut rifling. Stress is not good for strings of fire more than a few rounds. This is not anecdotal. I question where your data comes from.

While most aftermarket barrels are adequate for the majority of us, there is a difference in price if you want to go all out.

A prefit Bartlein from Bugholes in 6.5 creedmoor will cost you about $675 shipped plus or minus
And a Criterion or Shilen from NSS may net you <$400 shipped.

Not everyone needs the top of the line barrel. Personally I want a quality barrel that is straight, with a best reamer specs for my application and with very little runout throughout the machined areas. Whether a Shilen, Bartlien or a Krieger I know I will get the bang for my buck with those considerations. Expectations are critical. I would like a rifle to shoot 3-4 inch 20 shot groups or better at 600 yards. But that is me and what I think I can do with my shooting and reloading abilities.

What do you need or expect?