A few days ago this comment from the /r/collapse subreddit received a lot of attention.
I read that throughout history, when an empire gets to the point of having celebrity chefs, it inevitably begins its downfall. Apparently this happened all the way back to Roman times. It's not a matter of cause and effect; celebrity chefs don't have a common thread of inciting violent empire-ending revolutions.
Rather when there is a common cause: first an empire allows its ruling elite to amass enough wealth as to allow "celebrity chef" to exist, then those ruling elite use their money and power to rewrite the laws in such a way as to propagate their own wealth even at the expense of the citizen's needs. At that point the empire becomes underfunded, as all of the wealth is captured by the ruling elite.
The poster goes on to describe the mechanisms by which this happens. Other than saying 'all the way back to Roman times,' they don't give much historical context though. Is there any evidence of this occurring in your area of expertise?
Two points on which to open:
First, I study food history, and insofar as we have any documentary evidence to work from, we're almost exclusively working from the materials of sorta-kinda celebrity chefs. Up to the early modern era, it's realistically only elites who wrote things down, so work that concerns non-celebrities (interpreting the term loosely) just isn't there. That leads to something of a bias in the material.
Second, looking for small-scale signals from which to draw conclusions about the progress of a culture or civilisation really doesn't work. This has been popularised by people like Jared Diamond, but it's not in any way good history.
There is an argument out there that inequality (not a small signal) leads to the downfall of cultures and civilisations - but it's mostly an argument advanced by economists, and not historians. Historians mostly look to widely disparate causes for those failures - climate change, defeat by other groups, famine, disease, and so forth.
But let's look at some of the evidence for celebrity chefs. Elites in almost all eras have displayed their power and wealth by means of food. This can be through conspicuous consumption (swans stuffed with goose stuffed with capons stuffed with doves, and the whole thing re-covered in the swan's feathers, only dyed with expensive saffron) as in medieval England, or through the provision of food for large groups of people (an obligation of kings in pre-Norman Ireland). It can also be through the celebration of food in poetry and art (10th century Baghdad, for example).
Some of these eras have given us named cooks. Others have given us documents which were clearly collated by cooks in elite houses, but whose names are not attached to surviving manuscripts. And some have given us other documentary evidence of people who were celebrated cooks, but of whose actual work we have no record. But there's no connection that can be drawn between the existence of these cooks and the downfall of the cultures in which they lived.
Picking a few examples:
The Kitab al-Ṭabīḫ is a book from 10th-century Baghdad, compiled by a fellow called Abu Muhammad al-Muthaffar ibn Nasr ibn Sayyār al-Warrāq (and mostly called just 'al-Warraq', for obvious reasons). It's a collection of recipes and kitchen wisdom (and poetry and commentary) collated from sources as far back as the 8th century, mostly from the Abbasid Caliphate. Evidence suggests that al-Warraq was collating this material for a patron of a rising dynasty in Aleppo. al-Warraq's book - and thereby his own celebrity status, in the context of the era - was so influential that you can see clearly text from it re-collated in a work called Kanz al-fawā'id fī tanwīʻ al-mawā'id, 400 years later in Cairo.
Next, we can look at Bartolomeo Scappi, a 16th century Italian cook. His Opera dell'arte del cucinare was repeatedly (pretty much continuously) reprinted from its publication in 1570 until the 1640s, well after his death in 1577, which puts the works of many modern chefs into some shadow. Scappi worked for several cardinals in Rome, and then for Pius IV and Pius V in the Vatican. The Vatican's influence - and that of Renaissance Italy as a whole - could not be said to be in decline at that point.
We can backtrack a little to medieval Ireland, wherein the rank or title of briugu, a sort of hospitaller, is defined by providing food and drink to guests. These aren't strictly chefs, but they're people for whom in many cases lasting fame derives only from their provision of food - Buchet of the Laigan, Mac Dathó and Blai Bruigu (a host so synonymous with the rank that it's effectively his name) - are known pretty much only for this. The 6th and 7th centuries when these people were around were part of a historical tradition that continued up to 1169 and the arrival of the Normans, and continued beyond that as well in many parts of Ireland.
And you can also look at Mrs. Beeton, who was in effect a celebrity chef (leaving aside that she doesn't seem to have been a great cook herself, in reality) well before the fall of the British Empire, or Escoffier, who could be said to be the most celebrated chef in Western cookery.
Undoubtedly there were some such chefs and cooks who were prominent just before their cultures disappeared, for whatever reason. But I'd make the argument that we can pick those out only because there are always notable cooks around.