Simulation systems can be very useful assets for fun gameplay, if you make a game that can make use of them. Immersive Sims are essentially all about this. They create a bunch of systems that can interact in all kinds of ways, and then they let the player figure out how to make use of them in whatever way they want.
The issue is these games are just making these systems without any way to take advantage of them. If the nails being long made you better/worse at things, and the nail clippings could be combined with other items to make potions or something, it could actually be a cool mechanic. Just doing it for “fidelity” isn’t useful though and usually just a waste of time/money/effort.
It can also make the incredibly tedious and irritating. Elite Dangerous is an incredible simulation of our galaxy that has terrible gameplay for your average player.
The simulation isn’t the reason for that. That’s just the design of the game. Plenty of people enjoy the Truck Simulator games. Elite is basically the same thing, but for space. Also, I wouldn’t call it a “simulation” of our galaxy, but a simulacrom or representation. It’s not changing. The groups expanding and building in that, the economy, and those systems are simulations, and they actually provide content for the game, regardless of if it’s enjoyable in your opinion.
Simulations that create content are when we should create simulations. Simulations that consume resources and don’t enhance the game should be avoided.
