Hi Suliman,
I think the problem really comes down to the goal of survival games.
I think the main goal of any survival games is to, well, survive. In order to survive you will need to manage different resources and dealing with hazzards in an environment etc.
When you set up the basic, no longer need to worry about surviving, you have actually finished the goal and the game is over.
You have found the solution to the puzzle, of course you will feel bored after that.
Games like Don't Starve varies the environmental conditions every time you start a new game to change things around, but that does not change the fact that the game will end.
I don't think there is anything wrong with city-buildings/sims/survival.
Like you said, it is just the nature of it.
You simply cannot make a survival game that forces you to stuggle on surviving constantly.
That is like a puzzle with no solution, it is not a puzzle.
Maybe, instead of making one game that lasts forever, how about making it worth re-playing?
Or maybe, like Minecraft/Terraria/Don't starve etc, survive is only one aspect of the game. Building stuff and exploring dungeon and what not can also be fun.