There are several reasons why the behavior may seem like a robot. Life is the best program that has ever been invented.

Specificity of Interaction: Proteins interact with specific targets in a highly selective manner. This lock-and-key model gives the appearance of a "purpose-driven" process, much like a robot carrying out a specific task.

Self-Assembly and Folding: Proteins spontaneously fold into their functional shape based on the underlying physics and chemistry. This self-assembly might look like a well-programmed process, but it's guided by the minimization of free energy and is determined by the amino acid sequence.

Cascading Effects: Cellular processes often involve complex cascades where one reaction triggers another. The high level of coordination might seem like a meticulously planned operation, but it's a result of evolved pathways and feedback loops.

Error Correction and Quality Control: Cells have mechanisms to correct or dispose of malfunctioning proteins. This built-in quality control further contributes to the impression of a highly efficient and error-free system, akin to an automated assembly line.

Evolutionary Optimization: Evolution has shaped proteins and cellular pathways over millions of years. The efficiency and specificity are results of natural selection favoring mechanisms that confer survival advantages. This long-term optimization might look like engineering, but it's a product of iterative natural processes.