Why don’t the cells that make up the plant separate?

Compared to the cells of animal organisms, plant cells have an important difference – a solid multilayer cell wall containing pectins, cellulose, hemicellulose, etc. The walls are penetrated by various intercellular contacts, primarily plasmodesmata. The cell walls of plants form a single structure. You can imagine plant cells as pills in a blister: the blister will be the cell wall. The cells do not separate for the same reason the blister of tablets stays the same – the material properties and the continuity of the package design.