A 58-year-old woman with hepatitis C virus (HCV) infection presents with progressive jaundice, ascites, and hepatic encephalopathy. Liver biopsy shows extensive fibrous septa dividing the liver parenchyma into irregular nodules, with loss of normal lobular architecture. Immunohistochemistry reveals activated hepatic stellate cells expressing α-smooth muscle actin (α-SMA). Which of the following best explains the role of stellate cell activation in the pathogenesis of cirrhosis in this patient?