While I tend to dislike and avoid statements that are worded as absolutes, @Tai_MT
raises some fair and important general points.
I think one of the main takeaways is making sure that your maps are designed with reason and purpose. I have seen games that do this in various ways.
Such as having a cave in instead of a dead end. A cave in implies that there was something beyond that might have made sense, but now it can't be reached. Unless, of course, you designed a way to get through it. Or having a mine instead of a dungeon. Mines can be branching and maze like and convoluted. They can have tunnels that end abruptly. Why? Because whatever they were mining ran out.
Or as Tai_MT referenced. Maybe having something worth visiting at the end of a side path. Like a library, or laboratory, or storage area, or whatever.
If you are going to have a dungeon, the layout should make sense. Now that doesn't mean the player has to be able to determine what every room was for. Especially if the dungeon is old. But having some visual or lore indicators can be fun.
The concept is the same for any location. Buildings should be designed in a way that makes sense. If there is a branching path in a forest, why is it there. What was it for? Maybe it leads to a cave or a remote pond or waterfall or secret grove or burial area or something. Not just a dead end.
Paths generally lead somewhere.
And I am a big advocate that location of treasure should also make sense. Now, I will still play and like a game where it doesn't. Like why is that treasure chest that is just sitting out in the open still stocked with stuff? Why hasn't someone taken it already? I'm looking at you Wizardry 8. I love that game, but why are bandits walking right past the treasure chest sitting by the road?
Why is there even a treasure chest at the end of that path or tunnel or whatever? Who would have put it there and why?
The same goes with the contents. They should make sense. Both for your game and for where it is discovered.
Again, I won't despise a game that doesn't follow simple rules of logic, but if you are asking the question for your game design, then I recommend applying logic and reason to every design aspect of your game.
The earliest games that I played were designed where if there was treasure, it was because it was usable. And you didn't leave anything behind. And a lot of games didn't even have places to buy or sell items. You found whatever you found. There was some value in that. Although I don't generally subscribe that those design choices any more.
I also have to be very careful about this. I plan on having a very complex system for locks and traps for containers and doors. But those have to make sense. Why have a door that has a mechanical and magical lock, a mechanical and magical trap, and then the room beyond is just empty? Or it is protecting a simple storage room? And any treasure is just general crap. That doesn't seem to make sense.
So, making a long response short, design everything in your game with a purpose. That includes maps, treasure, quests, skills, classes, lore, etc.
I hope the responses that you receive are helpful and good luck!