Simulated universe might have more live-density per state space bit then host universe. I.e. most power of host universe might be dedicated to running "stupid"

Simulated universe might have more live-density per state space bit then host universe. I.e. most power of host universe might be dedicated to running "stupid" processes (using, for example, 10^200 bits per sentient being), while simulated universe might be better optimized (using only e.g. 10^40 bits per sentient being). So even if simulated universe is much smaller, it still will be more likely to "be born" in it. (This argument is similar to other arguments against your claim, but rephrased)