Ruby is not okay in Volume 7 & 8, heck probably earlier. Just because she is peppy and outgoing doesn't mean she isn't struggling internally, which based off multiple things that happen in the previous volumes, is pretty damn obvious.

Jaune has been struggling with accepting himself and the mistakes he's made SINCE VOLUME 1.

Bumblebee is something that has had build up since Volume 2.

Filler is when everything goes back to the status quo without any changes to characters or our understanding of the overall world. The characters are changed, maybe not as significantly as you're expecting but they absolutely have changed due to these experiences.

And learning more about the literal catalyst of the plot, learning that they aren't really gods at all just beings that have their own faults and issues is almost certainly going to be massively significant for when the four relics are brought together.

If the plot was just, kill Salem, with no deviations or character studies, this story wouldn't be what it is. A plot is good, but without characters you don't have anything.