As a relevant data point. I did a PhD because I wanted to learn a lot more about Computer Science. I did most of it while working at pretty good software deve

As a relevant data point. I did a PhD because I wanted to learn a lot more about Computer Science. I did most of it while working at pretty good software development firms. Most of the people I work with have PhDs. They use some of what they studied at work, and I doubt undergraduates would be nearly as effective. There are a lot of advantages for PhDs in CS, if you like learning and studying. If you don't, there's really no reason to do a PhD, you're not going to get an outcome that you'd like. The types of jobs that work well for PhDs require (at least) some continuing research.