Why is the subject not as clear when shooting at night as it is during the day?

Question

Photo

Tell me why, when shooting at night, the object seems to lose sharpness, does not visually move.
Even on the Christmas tree you can see that in the focus area it is not so clear.
The shooting was done from a tripod. ISO 1600, aperture 4.0, shutter speeds 1s-0.10s.
Or is this inevitable if you take pictures without a flash?

Answer 1

Well, if the object (tree) does not move, the earth does not shake! and the camera is of high quality, it should be sharp as during the day, only darker.
You can pre-raise the mirror + add a 2-second shutter timer so that the camera does not shake