I'm a yoga therapist, and we see a lot of collapsed, slumping posture in people. Particularly over 50, it's epidemic. Forward head posture, a.k.a. hyperkyphosis causes a lot of problems, including neck stiffness, back and shoulder pain, headaches, and more.
In its advanced stages, forward head posture, a.k.a. hyperkyphosis becomes a serious health issue, putting people at risk for many of the same issues as osteoporosis as they get older. Research is only beginning to highlight this issue, so it's not widely discussed yet.