Yeah. Elon Musk's argument was that if we assume any improvement rate in computers at all, then one day it will be affordable to simulate entire worlds, and therefore there are billions of simulations for every real Universe, and therefore we're likely in one.
But, like most arguments, that one is wrong. He seems to be under the impression that it's inevitable that computers will improve indefinitely, and that there's no limit to how complex and powerful they can become while still remaining inexpensive to mass produce. But there's no reason to think that is true. Just because there's a rate of improvement now doesn't mean it won't taper off and eventually flatten in the future.
Also, his thinking is sloppy.