This paper presents a comprehensive survey and analysis of the applications, innovations, challenges, and future developments of blockchain technology in IoT systems. The study uses a systematic review of current literature to examine how blockchain can address issues such as scalability, security, and interoperability within IoT networks. This work contributed on the integration of blockchain with emerging IoT technologies, highlighting the potential improvements in system efficiency, data integrity, and secure communication. Its contributions also include the identification of scalability solutions that can enhance throughput, reduce costs, and increase the overall efficiency of blockchain and cryptocurrency networks. The paper also explores the potential of blockchain to enable new applications across sectors such as smart cities, healthcare, and supply chain management. It also explains several practical perspectives on the current state of research on blockchain technology and identifies future possible directions for further research and development. Despite the promising advancements in smart contract, financial, healthcare sectors, challenges remain, particularly in achieving full interoperability and addressing privacy concerns. These limitations are discussed together with recommendations for future research directions to overcome existing problems and fully use the potential of blockchain in IoT ecosystems.