Neural Network Simulation - What Are the Use Cases?

In order to deal with so many time steps required for building up our state signal, we typically use specialized neural network architectures. For example, as a well-known long short term memory model developed by Zepor Reiter and Jürburgn Schmittuber,. what is better to have a physical simulation or to have this neural simulation? And such state transition model is here then, as I already told used for developing or training the reinforcement learning controller.