I'm not surprised this film is considered by name to be the mother of popular Bollywood cinema. I'm not an expert, not on the films nor the timeline, but I've seen a few modern ones and this film seems a pretty clear template for the later successes of popular Indian cinema.
A young couple struggles to keep their family going, to ease the burden they lend some money from a local loan shark. He keeps upping the interest, when Shyamu loses both of his arms things get really dicey. Shyamu feels ashamed that he's such a burden on his family, so he leaves them behind to fend for themselves.
It's really what you expect from a Bollywood film, but older. Which means, not quite as lush, somewhat slower and possibly even more melodramatic. And long, very long. It's not really the kind of cinema I like to begin with, to just get a more classical version of that made it quite the burden to sit through. I don't doubt the film's status, but it wasn't a very pleasant watch for me.