I'm currently approaching the end of graduate school in biology, so my experience only partially covers your question. That said, I don't think you should get a PhD. The worst part about graduate school is that you have to work on someone else's ideas instead of your own. The fact that you're considering graduate school means that you will probably have a viable idea someday, and you'll find that your pursuit of that idea will be delayed until you've finished your thesis.
Another problem is the opportunity cost, you loose four to six years of your life that you could have spent doing something meaningful, or at least accumulating resources. That might not seem like a big deal right now, but it will become a serious issue after two to five years.
Not true in the life sciences either. For one you usually pick a group that's working on problems that interest you. I always got to work on my own projects as long as they fit in the broader interests of the group, which interested me in the first place
Another problem is the opportunity cost, you loose four to six years of your life that you could have spent doing something meaningful, or at least accumulating resources. That might not seem like a big deal right now, but it will become a serious issue after two to five years.