A PhD especially in a technical field gives broad insight to problem solving full stop, or at least someone without severe self-esteem issues should consider that is the bar they've cleared. I have a PhD and wormed myself into tons of low positions, doesn't anyone else want to know how the sausage actually gets made?
For a software developer with a regular STEM MSc, there is more of an upper, less of a lower bound, but I'm not planning on testing out those upper boundaries (like, can you rise to C-level of a large corporation? Sure can, but a PhD makes it much easier where I'm from).