The only reason I argue with you to hear why I am wrong and see arguments against, not for. This is exactly the opposite of confirmation bias.
And it seems there are things going on here one on top of another. First you obviously enjoy an access to more gear and skilled labor than many of us here, such that you don't value penny saving and don't understand a value of simplicity over external paid services. Second, it seems our usage of terms leads to confusion, well, apart of "doctrine" obviously.
It seems to me that you use "prefit" as a synonym for "savage factory or some cheapest junk barrels" and in your mind you compare that to some high end boutique product, polished by virgins on top of mountain at a full moon. I don't see why same high quality barrel can't be made to order as a "prefit" as in my mind prefit is just a factory spec with enough wiggle room to be corrected with setting a nut myself. So in your mind there is an obvious difference between "junk" and "quality", but in my mind there is no difference just either standard thread and type of mounting or custom fit to a rifle made one.
ARC Barlock is essentially a barrel nut, more parts for a little more convenience. Is there any problem with ARC Barlock or its ok because its boutique? Why a savage nut on a bartlein barrel is ok, but a more moderately priced "prefit" is not ok?
As for the shoulder and cut to action vs barrel nut arrangement - again, all you said is more expensive, labor intensive and requires more time than a nut and gogauges setup. You don't see any issue with that over quality advantage, whatever phantom or not. From my point of view this quality advantage is either not attainable or not reasonable for the extra cost. However from my point of view "take an action out of a box, buy a standard barrel, screw one into another, tighten the nut" is not even close to "send action to a smith to find out my specs, remember these sizes, order a barrel for my custom sizes, receive shouldered custom to size barrel, screw and tight to a specific torque and expect that all the above was done properly".