When to not use electrolytic caps at the input of flyback converter?
If you have a 3-phase power source with a neutral (as in your example) and a full-wave rectifier you don't need reservoir capacitors at all for a switching power supply that can function with a smallish ripple voltage. So a relatively tiny bypass capacitor is sufficient. Graphic from here: 



If you have a single phase power source you need to keep the capacitor voltage high enough for the SMPS to operate even during the troughs of the input voltage, so you need a relatively large capacitor and a ceramic part may be impractical. 

Although ceramic capacitors have less in the way of a defined lifetime, they are not necessarily more reliable especially when you try to make something relatively huge. They also have unpleasant voltage coefficients, temperature coefficients and aging that mean you can't take the claimed capacitance at face value. I've also seen a number of infant failures in large value (very expensive) ceramic capacitors.