There is a surprising number of cabinets that don’t reach the ceiling. While we don’t know why exactly this is, it has been said that the taller your cabinets are, the bigger and more spacious a room looks.
If your cabinets don’t reach the ceiling and you’re looking to add a bit of height, you can simply close off the extra space above the cabinets. This can be done by placing a piece of wood that matches your cabinets and then going in and adding trim.
Alternatively, you could also add height by installing a row of thin cabinets above the original ones and painting them to match.