i think one thing about steven universe that i can isolate as objectively being a problem based on what i know of the pilot vs the show
is that i don’t think it should have been switched from fantasy to sci fi
to my knowledge the gems were originally more magic oriented rather than sci-fi alien oriented. and im not saying that there wouldnt still have been some marriage of the two ideas in an alternate product, but that most of their biology and abilities would have been attributed to “magic” rather than them being biologically non human and therefor subjected to like. physics and logic
and i think that would have just made more sense overall
“magic” as a source of the rules for your fictional world allows for much more flexibility than “aliens,” yknow? and i feel like a lot of the weird logical inconsistencies where the gems as a species are concerned would have been easily written off if they were magic, whereas them being aliens demands a whole other level of exposition and logic that the show just lacks
like, a big reason why i was so disappointed with the designs of many of the homeworld gems is that it doesn’t make sense for them to be super humanoid. up until then we had only seen the crystal gems, and it MADE SENSE for them to be humanoid-they liked humans and lived among them, so it made sense that a shapeshifting entity would look at least partially human to exist in a human world. thats totally believable.
but why would a homeworld gem want to appear humanoid? they dont have any of the same biological needs as human beings, so it makes no sense. they arent really even animals. at least an alien that has like, skin and organs makes sense to have like. a mouth, and eyes to detect light, etc. but the concept of the gems themselves, while cool, is too alien for the way theyre depicted
not to mention that the show itself is really inconsistent with what it attributes to magic. why do the gems refer to their own abilities as “magic,” especially at the start of the show? they also display abilities that are never explained (such as pearls sand-bending nonsense) that would have been really forgivable if they were just magic, but dont make much sense if they have to abide by the rules of. evolution and logic. like how did the gems evolve? they dont seem to be a part of any ecosystem, they have no relationships with any other species. its just weird
and its not like they couldnt keep a lot of the sci fi stuff and just attribute it to magic. but with magic, as an audience, u tend to give a lot more leeway when things don’t make normal sense, because magic doesn’t have to make sense. it just has to follow a few basic rules to maintain consistency.
i have no idea why the choice to make the show more sci fi focused was made, but i feel like it really takes away from a lot of what made the show enjoyable when the people behind it have to scramble to make explanations for ideas that worked better as magic. they also mix in really science heavy or more realistic ideas with ideas that are almost Completely magic/unexplained, which make the rules of the universe they live in inconsistent and sometimes hard to understand
i feel like it contributes to this feeling that while homeworld is cool and the show is still very emotionally compelling, the gems as an alien race feel kind of disappointing or confusing. like theres so much that just goes completely unexplained or is, inversely, completely OVER explained to the point where it highlights out the flaws in other parts of the story, that you just. have a hard time believing in homeworld as a fictional place. it just doesn’t feel real. it doesn’t make sense. and it seems like very little thought went into designing it.
it feels like sometime after season 1 they made a switch fully to sci fi, but that only left a a bunch of weird, unexplained stuff in the lore that never got resolved, and as a result when they tried to build homeworld it turned out less like a believable, mysterious place and more like a sparkling, underwhelming setpiece, because they dont know what this alien world would look like
tl;dr: idk i just feel like if theyd stuck to their guns with the magic business it would have enabled them to get much more creative without being bogged down in over explaining sci fi concepts that are most likely lost on their target audience anyway