Don't get a PhD because you think it will be good for random job opportunities. Get a PhD because you really want to spend a lot of time researching X very deeply.
Yes. I did this a few years ago after working for ~9 years. The trick is getting good letters of recommendation that far out. In my case, I got letters from supervisors/colleagues and applied to Masters programs, then used my Masters as a springboard to a PhD. It's been great, I would highly recommend it.