What complexity did DIY enthusiasts face before the curated kit solution?

Correctly sizing panels to the charge controller, controller to batteries, and battery bank to the inverter/load

Before the advent of pre-bundled, professionally vetted kits, the process of setting up an independent power system demanded significant electrical expertise from the user. The primary challenge was the necessity of calculating and ensuring component synergy across the entire power chain. This involved ensuring the panels produced enough power for the load while simultaneously ensuring the charge controller was rated appropriately for the panel wattage, and that the battery bank capacity could provide the required days of autonomy without solar input. Mismatched sizing often led to system failures.