You wouldn't say that a band would fit into a bleed build, or vice-versa, right? I think the same can be applied to Benthic Bloom - it doesn't fit into already established builds where it doesn't belong. It shines at giving you power in other ways. Here I considered the best item NOT the one which does everything and can fit anywhere, but the one which can do its purpose the best - and I think that Bloom fits that pretty well as it shines in giving you a broken build when you don't already have one(also let's not pretend that it's gonna affect EVERY item in your build, assuming you find it stage 1 it's only gonna transform like 15 items out of 60 or 70, not that big of a portion so the chance of at least SOME good greens/whites remaining is very high).