And that's why it doesn't really correlate. In the late 400s, East Rome and the Sassanids were doing just fine, not to mention the "Barbarian" kingdoms. And when you integrate periods, the gap around 476 smooths out. No-one even knew it when Rome fell, it was just a period of increased turmoil and slow institutional decline which was repeatedly slowed down and reversed. At any rate, we're talking about calling the Middle Ages the Dark Ages. The Medieval period wasn't even properly started when we see the lowest portions of the graph.

Very few historians, for a start. Custodians and art historians are a different category.

The gap reflects what's on display rather than what's held by the museum. The display is shaped by the pop history tastes of the public. Not to mention the Louvre simply specialises in the periods more known to the average tourist. Also, if you actually look at the graph, the late Roman period is the true nadir, followed by the period after Justinian's conquests. If this were an objective representstion of history, the contemporary Islamic and Chinese displays would have to be enormous.

And how is that a reason to promote long-disproved notions?

No self-respecting historian has called them that in decades.

Exactly. On paper, Long ticked all the boxes for a lasting career (Emmys, Golden Globes, name recognition), and it didn't really happen. No such thing as a sure thing, I guess.

It's an interesting what-if because the way Diane was in the last few seasons was the result of Long's telling the producers well in advance she was going to quit, so the writers scrambled to make her less organic to the show and less likeable. Notice how much less she interacts with people apart from Sam compared to the first couple of seasons, and how irrational she gets. Cheers managed to thrive after she left (even though I prefer the Diane years, the overall quality is just higher), and Long, sadly, got the short end of the stick.