This paper presents an extensive review of the recent advancements in telecommunications and the Internet of Things (IoT) with a focus on Micro-Electro-Mechanical Systems (MEMS) technology. The paper explores the different types of MEMS devices used in these domains, their applications, and the challenges faced by these systems. Additionally, the future potential and trends of MEMS technology in the field of telecommunications and IoT are also discussed. The paper also highlights the future of 5G and the need for RF passives, including wideband switches, adjustable filters, multi-state impedance matching tuners, programmable digital step attenuators, analog wideband phase shifters, phase-shifting hybrid devices, and monolithically integrated miniature antennas. The paper then provides an overview of the market exploitation of RF-MEMS technology, starting from its early vision and actual limiting factors to its current situation and future perspectives. The authors also discuss recent findings in the RF-MEMS state of the art research scenario. Lastly, the paper focuses on the future of 5G technology and the need for RF passives in this field. Overall, this paper presents a comprehensive review of MEMS technology and its potential impact on the telecommunications and IoT industries.