The Internet of Things has sparked a profound revolution in networking by enabling the collection of vast sensor data, serving as the foundation for smart applications such as homes, cities, and industries. However, achieving such solutions is challenging due to resource constraints such as limited computational power, storage, and memory in IoT devices. The routing protocol (RPL), the most commonly utilized routing algorithm, employs objective functions (OFs) to determine path selection based on diverse metrics. The accurate evaluation and testing of these OFs are paramount in developing effective routing solutions. This paper thoroughly analyses the results of testing standard objective functions, focusing on addressing load imbalance and congestion issues. The analysis aims to ascertain the suitability of existing standardized objective functions as optimal routing solutions for IoT networks, given the results of the challenges posed by load balancing. This paper evaluates the efficacy of various objective functions used in RPL, providing insights to improve the routing performance and evaluate IoT devices’ reliability, energy efficiency, load balancing, and overall network performance. The results of testing standard objective functions using the Contiki OS tool are meticulously compared. The analysis seeks to assess the suitability of the existing standardized objective functions as the most optimal routing solution for IoT networks.