Actually, training isn't essential either. Things just go better if you do some. same with long runs.
Not a clever conclusion. How many runners do the olympics or eveyother top class without training regularly. NO ONE. But without the long run many.
Besides for let´s say 1:41 to 4 minutes runs - 800m to 1500m ther´s no consistent physiology or methodology argument that can justify the need of long runs. Lydiard argument that runs longer than 1h30m is outrate. That are no physical evidence of the benefit of a long run except in the case of long distance as it´s the marathon and longer distances where the prblem that´s to take the energy from lipids.