Been flying my mav 2 pro & zoom since 2019. The motors post flight are always warm, but never hot. You haven't mentioned HOW you fly.... sport mode for long periods: or conservatively in 'P' mode, which might make a significant difference. Have you checked the air vents at the base of each motor? If you remove the rotors and physically twist the rotor housing, do they turn relatively freely (there will always be very slight 'clicky' resistance because of the magnets) or is there greater resistance than normal?
If the motor feels gritty when you twist it, try blowing compressed air up through the bottom vents (can of compressed air keyboard cleaner). Also visually check to see if the rotor housing is equally parallel to the stator base all the way round, the axle can get bent (this has happened with Inspire 3's that have been forced into the transit case with their props still fitted, so it isn't beyond the realms of possibility)