While approaching an intersection, a 4 door sedan in front of me rapidly applied their brakes to stop for a yellow light. I did not see they had stopped in time, so I rear ended them. The impact was so severe, the engine from my 2022 Odyssey was pushed into the firewall and most likely is totaled. If the Collision Mitigation Braking System (CMBS) initiated, it did not occur before I slammed on my brakes. The airbags also did not deploy. The car is undriveable. I was taken to the hospital and was found to have a hand injury from most likely my hand hitting the dash. My neck has whiplash and upper back/sternum is sore. I am being referred to an orthopedic surgeon for further hand evaluation. I am confused why the CMBS didn't react quicker and/or more aggressively as well as why didn't the airbags deploy?