There are many more things going on and interacting, which are the subject of intense research by the military.
See
http://2poqx8tjzgi65olp24je4x4n-wpe...tanding-and-predicting-gun-barrel-erosion.pdf and start at page 3.
Now, in the commercial world of rifle barrel manufacturing, lets imagine a scenario:
Both manufacturers know how to make a good barrel, and the difference that the quality and composition of the steel makes to their life.
By the way, no stainless steel is as good as the proper stuff that can go rusty if not cared for. But is attractive to those who prefer a low maintenance regime. It still can rust though. Good for other bits of a rifle, but a none-SS barrel would always be my first choice.
Manufacturer A maybe chooses to use the most durable exotic gun steel, if they can source it reliably, at added expense, and tooling wear. Their USP being that, whilst expensive they should last longer. Hoping that these gain a good reputation from those to whom this matters, e.g. the ones who wear out a barrel in a year or less, even keep a spare one pre-fitted, and the tools to screw it on themselves when they detect that the first is going off just a touch. They are not set up for high volume manufacture.
Manufacturer B chooses to mass-manufacture barrels that are just as accurate, from a perhaps slightly less durable but more economical steel, that is maybe easier to machine, in ready supply. Knowing that the vast majority of the final customers will never need, have any way of comparing, nor appreciate the possible benefits. They also want to mass-manufacture and sell to rifle manufacturers competitively (lowest bid wins).
Which also allows them to get the best barrel steel that they can afford, with volume purchasing. It might actually be better, even the best.
Here's an example:
Different business plans.
As for the powder manufacturers, they probably know how their compositions affect wear, but AFAIK none of them make any claims in this regard. Their drive is to offer marketing advantages such as higher velocity, better uniformity over large temperature variations, less copper fouling due to additives that somehow chemically remove it (and what else ?). Whilst re-formulating for REACH compliance. And coming up with marketing names such as "Xtreme", or just giving them silly names instead of plain numbers. Which I suspect may not be conducive to barrel wear considerations.
Also study
Smokeless powder - Wikipedia
Never seen a problem with double base ball powders such as BLC2 or Vectan SP7, and have used them for several thousand rounds, at recommended loads in supposedly boring calibres. Nor let the barrel get toasty hot.
Then there is the choice of calibre. A large case behind a small bullet (over-bore) running at the top end of pressures, inevitably funnels that blast into the throat more savagely than the boring old well-balanced designs operating at lower pressure. Some extreme ones are notorious "barrel burners".
If you choose one of these, knowingly, then factor in your re-barrelling costs, as they become a consumable, like tyres and brake pads on a vehicle. And could even be on parity with the costs of everything else per shot.
I think that, if shooting long range just for fun, and personal satisfaction, something as mundane as a boring economical durable .308 is still a viable choice, even if it tests your skills more than the latest whizz-bang. Which is surely the satisfaction.
But if you want to do this competitively, and aspire to reach the highest levels, you need to pay for the "best" stuff and keep up with the trends, which are sometimes outliers, right on the margin of what works, with no consideration of real-world durability. It becomes a very expensive game. Even then the best kit is no substitute for skill.
).
