We have loads of moss in our garden and grass (Oregon). I often wondered the same question. Usually when I'm removing it from my flower beds. I have yet to see any positive benefit to this kind of moss in flower beds.
"My Quasar is beginning to bloom. Looks all creamy white skirts to start out, then slowly shows the purple & orchid petticoats underneath. You are right about moving them around to see what they like. This summer when the temp hits the 90s it may…"