While all the factors listed can impact an economy, the most significant factor that has contributed to India's economic struggles historically is a poorly developed infrastructure. Inadequate infrastructure can hinder transportation, logistics, and overall efficiency, affecting industries and agriculture alike. This leads to higher costs, reduced productivity, and can limit economic growth.
However, it's essential to note that India's economic situation is complex and influenced by various factors, including those you've mentioned. But from a developmental and growth perspective, infrastructure has often been cited as a critical area needing improvement.