I think you should stop assuming you know what the vast majority of PhD think about doing a PhD. I'm a student myself and I've loved every minute of it so far. I use the tools I want. I work on interesting problems. And I pretty much make my own schedule. AND I get to help other students while I'm at it. What's not to like? Frankly, it's bliss.

I don't know exactly what I'm going to do when I'm done.

Granted, not everyone thinks like me. But certainly not everyone thinks as you do.