It fits with the idea of the universe having an orderly underlying structure. The simulation hypothesis is just one way that can be true. Physics being true is another, simpler explanation.
We don't know that FW is an illusion. If we did, that would be compatible with the apparent world being some kind of simulation. We also have very lite hope of knowing what kind of simulation we are in from the inside. So the illusory will hypothesis isn't giving us much information about the simulation hypothesis, and the simulation hypothesis doesnt give us much information about free will. This topic doesn't seem to go anywhere.
ETA:
The simulation hypthesis being hard to disprove means almost everything is compatible with it.
Similar to a game of The Sims the characters actions are chosen in advance.
A string of actions were your last action effects the next one and were actions are cancelled out and changed.
Your next action is to prepare a meal. You walk to the kitchen to start preparing the meal when you open the fridge and notice you don't have any food. The action is now cancelled and replaced with "Go to the store to buy food".