Another CDC page uses an analogy of grass being like your hair cells. If you walk over grass and bend the grass (listening to a loud concert) they'll return to normal after a short while. But if many people walk over the grass, it will die.

Also, besides the hair cells, loud sound can also damage the auditory nerve.

https://www.cdc.gov/nceh/hearing_loss/how_does_loud_noise_cause_hearing_loss.html#:~:text=Listening%20to%20loud%20noise%20for,neural%20system%20is%20generally%20permanent.