DecoPerson and noxToken are right about this being a general statement about computing and not present day technology. Whether or not the human brain can be completely simulated by a machine is still an unanswered question but nothing I came across so far convinced me that it's not possible.
While it's true that not all mathematical problems can be solved algorithmically, that doesn't limit at all the kind of things a computer can simulate. Most physical phenomena don't have a mathematically precise answer and approximations are usually good enough. I hope I understood you correctly there.
If you say "computers can't correctly model everything" then I probably disagree with your definition of a "model". In my understanding of the word the concept of correctness doesn't even make sense. I'm convinced that models should be first and foremost be judged by their "usefulness".
To make this discussion more concrete, it would be very helpful if you could provide an example of something that cannot be modeled with a computer.