I see it as a multi-edged sword. On the technical front, that is losing importance, publishing by chapter allows a reader to see if they like it without downloading the whole thing. Still relevant for many who read on handheld devices.
From the writer's perspective, it was covered in other posts, it allows us the flexibility to publish as we write rather than waiting until it is all done. For me, I value the feedback I get and can decide to change direction to please the readers who choose to speak up. The downside, as has happened to me already, sometimes a later chapter needs to be moved forward and integrated into the beginning of the story. That results in an almost new story, which is not a huge deal in he modern world of writing on computers.