This study focused on the performance of polymeric materials, which have garnered significant interest across various industries. The initial generation of polymeric insulators utilized materials like epoxy, silicone rubber, and ethylene propylene diene monomer for shed applications. Among these, silicone rubber emerged as the most promising material, as demonstrated through global experience. Researchers worldwide are exploring the use of micro, nano, and hybrid micro/nano inorganic fillers in base polymers to improve insulator durability and cost-effectiveness. The study focuses on the influence of fillers on thermal, electrical, and mechanical properties, as well as their resistance to corona discharge tracking and erosion. This paper highlights key advancements in polymer nanocomposites while identifying potential areas for future exploration within the realm of high-voltage electrical insulation. The use of various inorganic fillers has demonstrated significant potential in enhancing aging resistance, thereby strengthening the use of polymeric materials in advanced insulation applications for modern power systems.