Ranking the parts of the Snyder trilogy in terms of “quality” or “entertainment value” (not necessarily the same thing) comes down to taste and opinion. Obviously. I’d argue, however, that that ZSJL is the most conventional and orthodox of the three. MOS might be a close second; but it employed some infamously controversial choices. And BvS is an unabashed and unapologetic deconstruction. ZSJL, on the other hand, seems like something that would’ve been written for a mainstream graphic novel and fully approved by DC editors and executives.
Granted, such an evaluation is more obvious via “compartmentalization” — considering ZSJL in isolation. Conversely, it’s less obvious from an integrated, holistic approach. This is especially so if you despised BvS and were dreading the Knightmare plotline indicated for the unfilmed JL2/3. In that case, it might be tougher to treat ZSJL as a standalone “oasis” of normalcy.