I wouldn’t say one is easier than the other. Obviously for nighttime, the runway needs to be illuminated or pilot controlled lighting available to properly spot and line up with the runway as well as for depth perception needed for the round-out (flare).
What is not readily available is the additional depth perception offered by daylight flying as well as terrain and obstacle identification and avoidance that is offere during daylight operations. There have been plenty of accidents which have happened where a pilot has become accustomed to flying shallow approaches into an airport, then attempting to do so at night and struck terrain, buildings, sailboat masts, wires, etc because they were hidden in the darkness. It’s often recommended that you fly a little higher approach at night into an unknown or previously unvisited airfield at night and thoroughly review the chart supplements for the airport in question as part of your preflight.
Optical illusions are also more prevalent at night than day. Airfields with runways on an incline or sloping gradient will not be readily recognizable at night. Also runways which are narrow present hazards during roundout, particularly if the pilot is used to landing on wide runways which may make him misjudge his height above the runway during round out. Runway condition is another critical factor and it may be unadvisable to land on a runway which is not paved or is known to be soft or uneven. Runway incursion by vehicles, people or animals is another hazard which also should be anticipated prior to flight. Again the A/FD should be consulted and the width, layout and condition of the runway should be verified and anticipated as part of a preflight.
Often the most difficult thing about night ops is during arrival into the terminal area around the airport. It’s often very difficult to spot an airport, particularly in big cities and urban environments from the ground clutter and nearby city lights. Roads, rectangular, lighted parking lots, etc can often be mistaken for runways and it can be misleading. Often times the intensity of the runway lighting is less than that of the surrounding buildings and roads and most pilots will intitially visually acquire an airport from the flash of the rotating beacon light. It can also be especially difficult in a city like Wichita, KS with multiple airports clustered together or make use of runways aligned in the same direction. Again it’s helpful to study a sectional chart to see where the airport is located in a particular city, the direction you anticipate arriving at said airport in order to determine how you will maneuver to set up in the pattern. Often knowing the general area of a city where the airport should be will help you locate the rotating beacon in the ground clutter.
As for actually executing a landing at night on a properly lit runway, the actual act is not that different from doing it during daytime. It also has some additional benefits in that the airspace and traffic around the airport is usually less congested that during daytime operations and the air is usually smoother at night than during the day. But the limitations on visibility, peripheral field of view and darkness add in new considerations that a pilot needs to account for.