overdesigned

Overdesigned describes something that has been given more features, complexity, or refinement than necessary for its intended purpose.

An overdesigned product may be harder to use, more expensive, or less reliable precisely because of its excess sophistication.

The coffee maker was so overdesigned that making a simple cup required reading the manual.

The term implies criticism—that simpler would have been better—and often appears in discussions of engineering, software, and consumer products where elegance means restraint rather than elaboration.