My own experience during my PhD was that a few, if any, PI cared about your growth as a scientist. All they cared about was progress on their project which sometimes are the same. Most of the time they are not.
Some of my coworkers have shared some of those horror stories from previous positions, PIs insisting on primary authorship, making students do work for projects without getting any credit etc.
However, despite those abuses, I think the ultimate purpose of the PhD remains the same. Though perhaps it is easy for me to say because I didn't experience the abuses myself.