Matrices are used every where. Many real world problems are describe, not by 1 single equation, but instead by systems of multiple equations. Matrices are the fundamental tool used in organizing and solving these systems of equations.
Ecologist use matrices to explore the population dynamics of predator and preys (like foxes and rabbits)
Chemists use matrices to track the concentrations of reactants and products in a chemical reactor.
Physicist, mathematicians, engineers, computer scientists, economists, climate scientist, geologist, etc all matrices to solve a variety of different problems.
There isn't one typical problem where matrices are used, just like there isn't one typical problem where multiplication is used.