Besides being a door-opener for research jobs, pursuing a PhD is also a great chance for personal growth. You will be challenged on many, many levels and thus likely develop skills that you never knew you were lacking in the first place. In my view, the world becomes larger in grad school; you'll get to see so many hard questions and unknowns that your appreciation for existing knowledge will no doubt grow.

There may be jobs in industry that allow for similar growth, but they are certainly not the norm. It is easy to stay within one's comfort zone once one gets paid to do so.

In my (completely biased) opinion, doing a PhD is worth it for great and curious students that like to be challenged and that can afford 5 years, no matter what you plan to do afterwards (in fact, especially if you don't know what to do afterwards). You can always be a code monkey for 50 years after the PhD; it's hard to go the other way.