Central to scientism is the grabbing of nearly the entire territory of what were once considered questions that properly belong to philosophy. Scientism takes science to be not only better than philosophy at answering such questions, but the only means of answering them. For most of those who dabble in scientism, this shift is unacknowledged, and may not even be recognized. But for others, it is explicit.
Don’t believe scientific academics practice scientism? Want to make some heads explode? Just suggest that a logic course, taught in the Philosophy Department, be allowed to satisfy the undergraduate requirement for a math course. Grabbing, indeed.