The relaxation and stress-reduction benefit
Massage reliably reduces cortisol and activates the parasympathetic ('rest and digest') nervous system response — a genuine, measurable physiological relaxation effect, not simply a subjective feeling.
The muscle soreness and recovery benefit
Some research supports massage for modestly reducing delayed-onset muscle soreness and improving perceived recovery after intense exercise, similar in mechanism to some of the benefits associated with foam rolling.
Improved circulation, worth noting
Massage temporarily increases blood flow to the massaged area, which may support nutrient delivery and waste removal in muscle tissue, contributing to the perceived recovery benefit.
A reasonable way to think about cost and frequency
Regular massage isn't necessary for basic recovery, but can be a genuinely valuable addition, particularly during periods of high training volume or stress, for those for whom the cost is reasonably accessible.