Do simulators have the same hardware as real planes, or do they have a software model of the airplane?
If you simulated a broken AoA sensor, would the simulated plane behave similar to the real plane? Would the MCAS system have the same bugs in the simulator as in the one in the real aircraft?
Can you try new scenarios in a simulator, or can you just try scenarios that the simulator was designed to run?
On the other hand, if you're simply looking for some training hours on some specific basic scenario and/or aircraft, the simulators can be a lot rougher and still be certified. I "flew" on an airliner manufacturer designed simulator, and everything from the instrument panel to the hydraulics simulating the small impact when rolling between plates on a concrete runway felt pretty damn real.
For more basic stuff, even X-Plane exists in an FAA-approved version.