Oh look talking about the quality of RWBY!
Vol 1: Mediocre Plot with heartfelt characters, charming world, bad animation (except fights), badass music (arguably the best thing out of RWBY in general), and funny/cute/enjoyable.
Vol 2: Average Plot, still heartfelt and enjoyable characters, charming in general, badass fights, better animation (except for absolutely God awful run animation of Cinder on a roof......seriously that was bad), still amazing music, and funny/cute/enjoyable.
Vol 3: Plot makes Volumes 1 and 2 completely worth it and connects them wonderfully (after seeing Vol 3 Vol 1 and 2 become sooooo much better), slightly less badass fights (some not all, still very high tier), music remains spectacular, animation is again greatly improved (still not good obviously), and still very charming (and if you are very attached to the characters this will be the best Volume).
Vol 4: Best in terms of plot and story telling (yes it is despite being slow), fights are hit or miss but also has one of the greatest fights in RWBY along with the worst fight in RWBY, MUCH BETTER ANIMATION, the music will never stop being amazing apparently, and has lost most of its charm (what made Vol 1-3 enjoyable as a cute show is mostly lost). Still my favorite Volume though (Weiss MVP from here on out though).
Vol 5: 50/50, some awesome story moments followed with some awful story moments with cool fights that are interrupted or downright ignored (one of the best fights in RWBY is here but also some of the most awkward confrontations ever), the music is the saving grace as always (Jeff is a musical genius), pretty much all the charm of Vol 1-3 is again lost and likely will never come back, animation is again much improved however characters will feel robotic at times, and the Volume has some very cliche moments. I do not dislike this volume however I deeply hate portions of it (also Weiss literally became tied for my favorite character along with Qrow).
Apparently Miles and Kerry hadn't finished writing the script for Volume 5 when it started airing so I'd argue that was a major factor along with them blowing their budget and time on the three character shorts (which had great fights and good story telling).
All in all my favorite part of RWBY was seeing how something tiny blew up into what it is today, the fandom was awesome (pretty toxic nowadays though), and the music deserves all the recognition ever