Why are cells in organisms typically small?

Cells tend to be small because their high surface area to volume ratio allows for more efficient diffusion and exchange of nutrients, oxygen, and waste compared to larger cells. As a cell increases in size, its volume expands faster than its surface area. This imbalance means that a larger cell would have insufficient surface area relative to its volume to efficiently absorb nutrients at a rate necessary to sustain its function. This also means that many small cells can transport materials more rapidly than a single large cell. This efficiency in material exchange is crucial for the cell's survival and function. Additionally, small cells are easier to replicate and replace when damaged, ensuring continuous functionality within the organism.