Let us consider the 'big Empire' concept talked about by Joseph Manola in his (excellent) WFRP reviews. So we are on the same page, let's say that it can be expressed in the following way:
The Empire [or other generic Realm of Men] is big, but hollow. Between the cities are deep forests and mountains. There are few roads and fewer people; dark things lurk there. A fragile connection between towns and cites is maintained. The cities are full of people and wealth, protected by walls and cannon - but the a different darkness lurks there, in the sewers and slums and secret cult meetings.
Now, I realise that this could describe quite a few fantasy roleplaying settings. You can buy more things in cities, and the perils in them are likely to be different. But the Empire and the Old World will do best to illustrate this.
What if we deliberately invert this? I'll maintain (something like) the Mitteleuropean setting of Warhammer, for ease of reference.
***
We find ourselves in a world where the cities have been abandoned, with only high citadels enduring in the ruins of broken stone and crumbling houses. The plague took them, the famine took them - the rats took them. As the soldiers that still defend a few harbours and bridges might tell you, there is such a thing as Skaven.* Some brave or mad fools try and find wealth in the abandoned cities - a fruitless errand, for so little was left there.
Resettled, the countryside is full of wealth and well-populated. Population density is lesser than in cities, of course, but farmhouses are filled by extended families and household servants. There is no tiny isolated community as such; every village can produce a sufficient numbers of able-bodied workers or fighters.**
Trade goes on, but there are few places where merchants are permanently gathered. Rather, fairs are held at periodic times throughout the year in suitable locales. Even the grandest of these do not erect permanent structures to facilitate these. Merchants are not quite nomadic; they will rather store goods and coin in secure compounds in their own village.
The King? Only the greatest of local lords now, burdened with the expense of the royal progress. It would be unwise to tell him that, though. Besides, someone is expected to lead, or look like they are leading.
The great (though not sole) deity of these lands is Ypsilon, Lord of the Plough. Ypsilon of the Straight Furrow, Ypsilon of the Hedges, Ypsilon of the Silver Sickle. He is said to have been the first man to clear the fields and grow wheat - and then to defend those fields. His clergy make ritual journeys about the field boundaries, sanctifying the crop. The faithful are expected to pay a great deal of attention to the calendar, to set about their labours without complaint - and to take their spears with them to the field. The Harvest Festival is pretty hardcore. There are no cathedrals for the overseers of the faith - they sanctify the roads while the parish clergy bless the fields.
Learning is not found in the urban schools or universities, but in the independent monasteries set in fertile fields. High walls and full storerooms protect the libraries, as monks gather to dicsuss faith, magic and natural philosophy. Each monastery may evolve a particular speciality - alchemy, geometry, metallurgy, enchantment. Pilgrims wending their way between them carry books, ideas and devices. Each year, the world is further revealed.
Life in the country is good; a full day's work hopefully means a full belly, and the villages are safer by far than the towns. But despite this, there are whispers of rites in thorn-choked places, beyond the field edges. Worship of the gods of unbounded nature; the gods of unearned abundance, of choking rot, of hateful cold and of raw meat. Who knows what the villagers are hiding behind their hospitality? What lurks in the shadows of the orchard? What force could shatter a millstone?
I started with Early Modern Europe and I turned it into something like the Dark Ages: a loose net of civilisation, rather than points of light. A bit it of makes me think of 17th century Puritan New England, as well. Something far more focused on 'rural feudal' I suppose. But despite the bucolic edge makes a difference. Secret cults in creepy forests or isolated villages are perhaps expected; secret cults in hospitable taverns and village greens, perhaps not.
*Rather like Vermintide, I suppose. Not that I've ever played it.
**This isn't quite 'Tory Utopia'. But a certain form of agrarian conservatism would be at home in it.