Comment by Revanche1367

While this is somewhat true, people also overstate how narrow a Phd student’s general understanding of the field really become as they specialize. For pretty much any serious field, specialization is inescapable without spending decades minimally studying the field via many branches, but a Phd isn’t just preparing you to have a specialized understanding of a specific branch within the field, because very often contributing something mostly new and worthy to that branch requires a mix of depth and breadth, the proportions of which depend on the exact field, branch and specialized topic. Most Phd curriculums I’ve seen still require students to take several advanced courses outside of their main topic area and take exams in multiple areas within the field. Somebody working in only one area would need to have at least graduate level understanding of multiple branches to get through these. I have also seen Phd students who are not broadly interested or comfortable in certain core branches of their field so there are all types and different requirements for different programs.