Hang out and Enjoy the Degeneracy

When writing a long, more serialized story on ao3, how do you prefer for things to be broken up?

Each distinct arc is its own fic? It’s all one fic all the time that keeps being built onto? Certain more similar arcs are grouped into fics but after a big change it’s a new one? Or maybe each similar arc is a fic in a series, with the entire story also being part of a bigger one? Or something else entirely because seeing things in 2 series could be discouraging or less likely to be picked up.