I forget where I heard this one, probably a YouTube video.

But yeah, the idea is to have a setting that is unstable. A brewing conflict may be on the verge of erupting, or already has. A drawn out conflict is close to a deciding point. A safe place is no longer safe, or just never was. Whoever was in charge is no longer in charge, and others vie for power, affecting everyone. The setting may be an unknown frontier (to the players).

This is opposed to say a peaceful village with no real troubles, a well fortified base camp, or a powerful kingdom that’s been ruling peacefully for some time.
Now, you might have a peaceful setting that is then thrown into chaos shortly into the game. However, I would make the case to have the setting in disarray from the get go. I think there would be more for the players to build off of during character creation, they can have more meaningful goals, etc. I also think there would be more for the GM to build their world up from.

Having a stable setting can make the players unnecessary. If the setting has been handling itself and its problems for some time, what’s to say it can’t continue to do so? The players are more replaceable. Also, it’s hard for players to change something that’s been secure for a long time.
In an unstable, more dangerous setting, the players are more necessary because they’re all that’s available. They also have more influence on how things play out, more able to cause change.

An unstable world also invokes more uncertainty, more risk, more danger, which is generally more exciting. In a stable setting, if you fail, you might be pulled to safety to recover, or even if you die, backup can just come in and solve the problem.

I think an unstable world would cut down on aimless wandering too, since players won’t be waiting for something to happen, meandering. The GM will have more to work off of too, more to throw at the players.

That’s my string of thoughts on the matter. It’s advice I wish I had heard earlier, because I’ve run into problems when running relatively peaceful settings.