What are the reasons behind marking neutral and line terminals on a power supply AC input?
One example where Live/Neutral does make a difference are some lamp fittings.
For E27 and E14 fittings the "screw" part is more likely to be touched by the user when changing the lamp. That means that the screw part should connect to the neutral instead of live.

The other fittings are symmetrical so there is no difference.



Regarding electronic devices I have yet to see an example where the mains connection is not symmetrical. That makes sense because as remarked in Justme's answer, it depends in which country you are if the Neutral and Live are always connected in the same way (UK plug) or that they can be swapped (EU plug).
To be on the safe side, the equipment is designed such that the live-neutral connection can be swapped.