> What caused the collapse of the Roman Empire? More than 200 explanations have been proposed, but there is no consensus about which explanations are plausible and which should be rejected. This situation is as risible as if, in physics, phlogiston theory and thermodynamics coexisted on equal terms.

(From the linked page https://www.nature.com/articles/454034a).

Multiple problems here. My understanding (as a pretty-well-read-for-an-amateur in the subject) is that this claim is overstated. Most historians today seem to agree that

- Rome had long since stopped being the capital city of the Empire. It wasn't even the most important city in Italy in the Late Empire. - Romans at the time wouldn't have known about a "fall." It had been a long time since Italians ruled the empire. The empire simply passed from rule by Romanized-non-Italians to foreign conquerors. - The Roman empire didn't fall, it moved; it persisted in the East until the fall of Constantinople in 1453. The Emperor in Constantinople would have called himself 'Roman' for those 1000 years, and the term 'Byzantine' is a later invention. - There were lots of contributing factors to the fall of the Western Empire that worked together. Some of these were external (migrations of the German tribes, invasions), some of these were internal (cultural divergence between East and West). There is some debate about the relative importance of these different factors.

The question can't be answered not just because the answer itself is complicated, it's because the meaning to the question is ambiguous in a way that the questions answered by thermodynamics are not. For related, more specific questions, we actually do have consensus on the answer.

It's also cherry-picking one example. There are lots of cases of historians coming to a better understanding of an event over time, and concluding earlier explanations of the event are incorrect.

While I can see why it would be good to have a "science of history," we've proven largely unable to do this in much simpler areas. Analytics applied to the game of baseball, a game where we have complete information about everything that happens today, including where people are standing on the field and the ball's spin rate, has only recently gotten to the point where there's a quantitative science around it. Human history is a lot more complex than baseball.