Why did Classicism make Rembrandt’s realistic style less fashionable?

The rise of Classicism in the late 17th century, imported largely from France, brought a fundamental shift in artistic taste that rendered Rembrandt’s style less fashionable.1

Classicism emphasized universalizing and idealizing approaches, valuing harmony, proportion, restraint, and clarity of form. In contrast, Rembrandt’s work was defined by an uncompromising realism that prioritized the particular over the general. Critics influenced by the new classicistic ideology—which favored antique sculptures, systematic training, and established rules of anatomy and perspective—viewed Rembrandt’s approach as a challenge to these standards.123

Because Rembrandt relied on nature rather than these idealized rules, his work was sometimes criticized by younger peers as being "old-fashioned" or lacking in refinement. Despite this shift in fashion, Rembrandt remained a towering figure, and his genius continued to be recognized by many connoisseurs and collectors throughout his life and beyond.14