I am curious though; besides the hard-to-reproduce silhouettes (due to LEGO) is the similarity just a quirk of designing a team? Like, there are iconic teams that have variety in their silhouettes, but then just as iconic teams where their designs are near indistinguishable and that still work.
At least, I think they do. I'm not saying one is better than the other, it just... ... reminds me of my opinion / spicy hot take that the Ninja Turtles are better when their designs are more similar with only small variations as opposed to exaggerated visual differences.
I'm trying not to say too much since really I haven't even looked that deep into Bionicle in years. They may also just suffer from being too similar in vibe. Not sure if the cartoons or games ever did much to give them distinct personalities.
I'll end on a fun personal story. The Bionicle: Quest for Makuta boardgame was really neat but me and my siblings never played it correctly. Instead, we used the hexagon board pieces as an RPG map and printed out custom armies of Shy Guys and Warhammer Lizardmen to do war with. It was fun.