Here's why:

* Fluid Matrix: Blood's matrix is plasma, which is a liquid consisting of water, dissolved proteins, electrolytes, nutrients, and waste products.

* No Protein Fibers: Unlike connective tissues like cartilage and bone, blood does not have collagen, elastin, or reticular fibers. These protein fibers provide structure and support in other tissues.

While blood contains cells (red blood cells, white blood cells, and platelets), these cells are suspended within the fluid matrix, not embedded in a fibrous network.