Only last year has TRAI raised minimum broadband speed from 256 kbps to 512 kbps. And in 2007 TRAI had set minimum broadband speed at 256 Kbps. We probably had 128 kbps as minimum broadband speed before 2007.
So we're not stuck at 512 Kbps since 10 years. 512 kbps is a luxury we just got last year.
Many people don't remember that TRAI wanted to set 2 Mbps as minimum speed since 2009. They recommended a road map by which 2 Mbps had to be made minimum broadband speed by Jan 2015. But all they could do was raising the minimum broadband speed to 512 kbps in 2014.