if I can form any consensus
Forum much? -haha. There will be no consensus on anything.
It's the "one gun to rule them all" question. You pick two opposite criteria and ask which thing embodies both, without concessions. Or, in this case, a person picks one criteria while the other opposite criteria is an integral part of the object in question.
With two criteria you get a few answers, but also those who do not like those answers because they do not fit another criterion that the downplayer thinks is integral to the question. None of the most accurate AR rifles are "mil spec." That's why BCM isn't in the conversation if extreme accuracy is the driving criterion. It's not that BCM is a bad AR, it just doesn't focus on the criterion. It's a very good AR when reliability is the driving criterion.
Accurate guns need tight tolerances. Semi-auto guns need slop to run reliably. Our military needs to field firearms that function clean/dirty, wet/dry, and with debris trying to make the firearm choke. You don't get "mil-spec reliability" and national match accuracy in the same thing. The manufacturers that make tight-tolerance AR's still need high quality, consistent ammo. A high end rifle plus low end ammo is good (and better than average) but not extremely accurate.
It's even worse with three criteria because you get a Goldilocks question and have to ascertain the driving criteria. For example, "I'm looking for the most accurate, most reliable, lowest cost AR." That kind of question gets answered with entry level models since low cost usually drives. But could get answered with buying a high end upper and a lower cost lower that embodies either accuracy or reliability.
All this to say that divergent criteria won't net good information. Consider that precision AR's shouldn't use 5.56mm ammo because who wants inexpensive, high pressure, 3moa ammo in a tight chambered $2,500+ gun? Not me. If someone responds that they want the most accurate that can use 5.56... then the best accuracy isn't the driving criterion. If they respond that their budget is well below what the going rate of a premium rifle is going to cost... then the best accuracy isn't the driving criterion. Finally, if they don't handload to tune their ammo to their high performance rifle... then the best accuracy isn't the driving criterion.
Making a choice means that something else is not chosen. Decisions always require concessions.