With due respect to you, it appears to be you are new to the market... and of course, Zerodha has to prove that it has right system, capital, and technology in place. It is long way for them to prove they are the best. First, they have to get their system right...just by giving at cheap price does not qualify them as the best. we have seen many brokers offering cheap brokerage just vanish in few years.
Regards,
VDT