Carbon-based nanocomposites have been at the forefront of versatile materials for potential applications in energy conversion and storage, as well as environmental remediation. Superior properties, such as a high surface area, chemical stability, and tunable functionalities, have made them front-runners in the field of solar cells, batteries, supercapacitors, hydrogen storage, thermoelectric systems, water purification, and air pollution control. The real-world application is inhibited due to several limitations such as scalability, higher production costs, limited durability, inefficiency in regeneration, and possible environmental hazards. A systematic assessment of these limitations along with proposed solutions in terms of green synthesis methods, advanced surface engineering, hybrid material development, and standardized testing protocols has also been presented here. Such challenges are envisioned to be overcome through interdisciplinary effort and lifecycle analysis that could ensure the translation of carbon-based nanocomposites from a theoretical promise to feasible, scalable technologies for global applications in the near future.