What you say is not in dispute- but not in this day and age.
Yes, 19th century secular reforms, a-la ‘Age of Reason’ and the Industrial Revolution changed a lot of it.
Even when the British abolished slavery, they were carrying it out for decades into the future through a surrogacy based on indentured labour. That’s how you have many people of Indian descent in such far-flung areas as the West Indies. Not to mention the Irish, who were also at the receiving end of this surrogate slavery.
As India modernises, change is bound to happen. They’ve already had a Dalit president.
See link in previous post.