Why did the Kolar Gold Fields mines close in the early 21st century?

The Kolar Gold Fields mines in Karnataka officially closed in 2001 due to a long-term decline in productivity.1

While the mines had historically accounted for over 95 percent of India's gold output, their economic viability diminished over time. The government had previously intervened by nationalizing the operations in 1956 to prevent an earlier shutdown, but this measure was ultimately unable to sustain the mines indefinitely. Following the final closure, the region experienced significant economic shifts, with many residents leaving the area or commuting to Bengaluru for employment.1