What a serious massage does, measured seriously.
It is fair to be skeptical of anything that feels this good. So set feelings aside and look at measurements.
Pain first: massage has decades of evidence for both chronic and acute relief. In one large randomized trial for chronic low back pain, massage improved function, and the benefit lasted at least six months.
The mind gets its share. Controlled studies record lower anxiety, heart rate and blood pressure after a single session, and larger changes across a course of sessions.
In trial after trial, the same quiet cluster of results repeats.
A luxury, yes, in the way good tools are luxuries. The body treats it as infrastructure.