EROEI is no more relevant to oil and gas professionals, or the oil industry in general, than the chemical composition of the dirt on the surface of Pluto is to you. No well, field, project, basin, play or offshore platform has ever been given the go/no go decision based on EROEI.
For some reason certain academics find it interesting, for example Charles Hall used net drilling yield and net energy circa 1981 to predict the end of drilling in the United States by the year 2000. The paper was probably actually written slightly earlier right about global peak oil production in 1979, resource scarcity was quite the rage back then as well. Charlie popped up again decades later when the next claimed global peak oil livened up the next generation of neo-malthusians.
In either case the resource pyramid concept is easy, as you move down within it, you open up more volume than the slice above. As technology improves, and economies of scale come your way, the price of that additional resource ends up being lower than it once was, pressuring the price on not only the marginal cost of production within a slice, but as we have seen with shale oil, it can even pressure the marginal cost of production in slices above, i.e. conventional oil produced by NOCs.