Like many (most?) medium-magic settings, the 5E D&D game I wrapped up last year assumed that artifacts and powerful magic items were mostly created in the distant past. Some of these supremely powerful items are essentially canned versions of adventuring magic. A Holy Avenger or Staff of the Magi was created for adventurers to use to fight monsters, or otherwise pursue adventurer-type goals.
But many other powerful items were created to solve more quotidian problems, or deal with day-to-day concerns. And that includes the problem of leadership and building stable societies in a world of chaos, magic, and monsters.
Consider, for example, Lunar Thrones.
Lunar Thrones are stationary artifacts that bestow a range of always-on spell-like abilities to an attuned ruler. Each Throne possesses different characteristics; abjuration and divination are common, including spells like Zone of Truth, Anti-Magic Aura, Planar Binding, Dimensional Anchor, and Hallow. The throne grants a spellcasting DC ranging from 15 to 20 depending on its potency, unless the attuned ruler already has a higher DC from class levels.
There are serious drawbacks to ruling from a Throne. It takes weeks to attune to a Throne. The attuned ruler also may not leave the vicinity of the throne without de-attuning from it; de-attuning causes a “hangover” effect, depending on the Throne, similar to the final clause in Raise Dead, or the last paragraph in Wish. The precise range one can travel while maintaining attunement varies from Throne to Throne, but is never greater than about a mile, and in many instances, is much smaller. Thrones also produce low-level side effects that are deleterious to the ruler's physical or mental well-being (for example, see the Minor Detrimental Properties table from 2014 DMG, pg. 220).
The Thrones provide significant magical protection, but were not designed to protect against physical force or other non-magical intervention, and they do not have offensive powers of any kind. Because the ruler can't retreat, relocate, or go into exile without losing control of the Throne, they are as vulnerable as an ordinary ruler to conventional takeover by force of arms, poisoning, or other tactics. So a Throne ruler is usually still reliant on a conventional military force and methods of projecting political and economic power to protect themselves. Scholars theorize that this is a feature, not a bug, in the eyes of whoever created the Thrones; to ensure there are ways to dethrone a ruler who becomes a tyrant.
Some societies have decided that the Thrones are worse than the problems they were meant to address, and have hidden their Thrones, buried them, or moved en masse away from them, to escape the succession of conquerors warring over them. Thrones are as resilient as other artifacts, and can only be destroyed through extreme and unusual measures.