Of course, but to blindly proceed toward the sea in sight in front of you hoping to reach the mountains behind you may not be the wisest course.
Oh, and by the way, there is nothing particularly inexact about demographics.
It's one of the more precise of the social sciences, and while it can only predict what will happen if present trends continue, it is very good at doing that one thing. It is also very good at telling how far along the process is and how fast it is proceeding.
In this case, in Europe, the process is well advanced and proceeding VERY fast. Just be aware.