Public schools in India also have teachers with excellent credentials (i.e. Kendriya Vidyalaya) but some of them just don't care to teach better. I've done my whole schooling from various KVs across Rajasthan, most of the teachers were actually quite good, but they weren't motivated to innovate and experiment. We were rarely informed about Olympiads, competitions, scholarships etc. Also, management was definitely terrible most of the time.