I read it, but I think I must have misunderstood it. The argument is based on the fact that it cannot be calculated in a reasonable amount of time ? I'm not ev

I read it, but I think I must have misunderstood it. The argument is based on the fact that it cannot be calculated in a reasonable amount of time ? I'm not even sure why the universe would have limits on computation. To put it bluntly: the mere existence of the universe/reality is magical, not sure why magic would have any limits in computation power (not saying there isn't any).