I am working as a mid manager in one of the HR functions in a well funded mature startup (decacorn) and will try to answer this. There is a huge misconception among tech bros about HR - HR only does rangoli, send mails, run POSH committees, hire & fire etc. However, the spectrum of HR is very wider than what it appears to external folks and it all boil downs to Ceos / founders on how they view the humans as resources.
A smart one knows that people can make/break the business in long term and explores the HR spectrum (learning, growth, wellness, culture, values etc.) to optimise for better business outcomes. End of the day, if my founder is not pushing me to execute creatively to manage humans, I will not do it. Same goes with any other function in any organization.
There are a very few Indian companies where HR can push back the functional leaders and call out on any possible employee exploitation. It all depends on how the top management want to play the people game and HR themselves being the employees of the company will have to stick to that.