There is a function where if you leave a door open for a while, the interior lights turn off to save battery power (assuming the interior light switch is on the setting to operate as you open the doors.)
Once this happens, even if you close then open a door, the lights do not come back on, you have to switch on the ignition to reset - I wonder if you have a problem with this?
Also, when the lights are set to come on when you open a door, when you turn off the engine and remove the key, the inside lights should come on before you open a door - to allow you to see inside the car - It would be interesting to know if this works, try it with the headlights on before you switch off the engine - I cannot remember if it only works when you've had the headlights on.
It would seem unlikely that all door switches have failed, possibly more likely to be a fault with the body control unit.