Jared Tyrell Leto wanted to manufacture replicants that could reproduce sexually, so he could make more of them and explore/colonize more of space. That's why it's a big deal to figure out what became of Rachel's child -- presumably, she'd be able to reproduce as well (this also goes mostly unstated).
It's weird how the movie can feel, if anything, even more abstract and subtle than the original in some ways, and yet so much more conventional and straightforward in other ways. It's as if they were aiming for something that would seem superficially more complex than the original, yet without anything close to the thematic depth. I do have to say that the thought of rewatching it feels painfully excruciating at the moment. But I'll give it more time. The original didn't become my favorite movie instantaneously.