Honestly, I feel like slice of life has fallen into a rut. Different settings could be used - not just the same old cities/towns. Or change countries. Do a little research on how things are different than in the US.
I do think that is a part of it.
Hmmm, without it being a truly mixed game? Unlikely but not impossible. Encourage other lines or other plots is the only way I can think of.
Or what about something different that isn't relying on all characters' life in danger all the time. A spy-based game, or something more action adventure-ish in plot? Or something set in other times? A historical game would be amazing as an example.
I just feel like there are settings people never use.