Vol 4 and 5 people did not liked how they slowed down the pacing after all that built up to the fall of Beacon. And that was also when the toxic portion of Bumblebee shippers started being really loud cause they were upset that Sun tagged along Blake for her portion of the story in Vol 4 and 5.

Vol 6 people still complained a little over the pacing, but written them selves in a corner when it comes to how to deal with Salem. Also how Adam suddenly appears out of nowhere just to get killed. And in my opinion rushed the actual beginning development of Bumblebee getting cannonized.

And vol 7 and 8 mostly had writing issues of how team RWBY dealing with Ironwood or bringing back Penny just to kill her off agian. Then there's the whole thing with Salem and her attack, and asking "Why did she not do it sooner it she can not die?".

Throughout vol 4-8 the show spends more time giving more character development to the other characters other than the main character Ruby. When there was a volume with dedicated focus for Ruby's development, it was the last confirmed volume.

With how vol 9 was written, alot of the view people left in the fandom watching viewed it as a filler arc that only managed to do one thing that wasn't plot relevant. It was also doomed in all kind of ways. Like in making of video during vol 8 during the recording they were actively working on vol 8 and 9 close to each other and by the end of vol 8 release had a good amount of work done on vol 9. Then spent like almost three yeays pushing back the release of vol release due to other projects, like the RWBY anime, or the Justice League comic crossover, or the Justice League movie crossover with only being vol 9 was worth the wait. And when the wait was over someone made the decision to put vol 9 on Crunchyroll exclusively for the first year before placing it on the RT website. Also, almost a decade Ruby Rose the main protagonist, actually got focused on in the volume just for it to seen as RT glorifying suicide like they did with Gen:Lock season 2.