The slowdown is in the simulation, not in the internally perceived flow of time. The internally perceived flow of time would of course not change.
The problem is that an exponential slowdown at each level requires discounting the probability of being in a simulation by an exponential amount per level. So instead of being able to say that the weighted odds of being in a simulation are higher than the odds of not being in a simulation, you have to say that, at best, there's a small chance of being in a simulation.
The problem is that an exponential slowdown at each level requires discounting the probability of being in a simulation by an exponential amount per level. So instead of being able to say that the weighted odds of being in a simulation are higher than the odds of not being in a simulation, you have to say that, at best, there's a small chance of being in a simulation.