In the current work, the researchers examine 20 years (2004-2024) of literature on Industry 4.0 and IoT, visualizing intellectual organisations, knowledge sharing, and changes in themes. Based on data collected from 6,000+ articles scraped from Scopus and processed with VOSviewer, Biblioshiny, and Python, it answers three research questions: the creation of Industry 4.0 and IoT scholarship, market forces and market uptake, and convergences in technologies. Results indicate soaring growth in publications starting in 2016, with significant contributions from China, the US, Germany, India, and the UK. The study identifies a gap in the scholarly literature and in the uptake of IoT, with high implementation evident in the manufacturing and logistics sectors, whereas in the healthcare, agriculture, and building sectors, implementation challenges persist. It includes suggestions for what researchers should consider in the future, including socio-technical integration, cybersecurity, and sustainable digital ecosystems.