In a high level campaign I ran, I took the design philosophy that the villains were supernatural (e.g, dragon or lich), the average npc was weak (level 3 or less), and the characters were once-in-a-1000-years heros (level 10-20).
Every now and then they would have an obstacle involving regular humanoids or the local government and they had the option of just steamrolling everything (even whole platoons). It provided a great contrast to the magic-boss death matches and let the characters really feel special.
It also drove home that they were the only ones who could save the day.
Absolutely agree. I set a game in the real(ish) world once, so it was a setting where everyone knew the base "lore." It was so nice! I could reference things, name-drop countries, and introduce old grudges without having to exposition it all. People just got things. We've since done enough games on the sword coast that that works too, now.