What is the role of the intercellular substance in tissues? In which animal tissues is it especially developed?

The intercellular substance connects cells to each other. From it, nutrients and oxygen constantly enter the cells, which are involved in the processes of biosynthesis. And also decay products are released from the cells into the intercellular substance.
Connective tissue has more intercellular substance (tissue that is not directly responsible for the work of any organ or organ system, but plays a supporting role in all organs). It includes fat, ligaments, blood, lymph, bones, etc.