In my setting ... these things [high-magic items and events?] are actually very rare, it is only through the actions of the PCs that these things come to the fore.
I think this is an important thing that is true in most (maybe not all) games. The PCs encounter elements of the game world that the common person would never encounter. By virtue of that encounter and the PCs power the PCs then shape the game world in ways a common person would never dream.
I have always considered a person (PC or NPC) with a class to be a great rarity. Most people in the world have NPC classes like Commoner or Artisan. Even an NPC Warrior class character is far below what the lowliest of Fighters can achieve.
Consequently, the mere fact that the PCs all have a PC Class places them into an aspect of the world that is elite. I also frequently make that understood in my game because a 5th level Wizard may not be so tough in the context of the party and plot but, to the populace at large, it is extraordinary.
So when the 5th level Wizard has that one good Fireball spell but it doesn't take out the enemy Rogue who has Improved Evasion and makes her Reflex save...well, that's how combat goes.
... But if I was the Commoner apple vendor who just saw some halfling chick jump 6 feet into the air and dodge a roaring ball of fire that came screaming from the hands of that crazy-looking dude with the bat on his shoulder ... ...