Doing regenerative farming does not mean abandoning half a century of knowledge and technological progress. Rather, it is using all we now know and know how to do to heal the land and maximizing output. In a lot of cases yes, the output may be smaller of some crops, but the net total calories extracted might not be that different.
Not to mention, if your land is all but barren and it requires fertilizers to grow, when prices spike or supply disappears and the farmer can’t afford to plant…the output is zero.