That last episode sucked, from a plot and writing point of view. Steven is just a Deus-Ex Machina at this point- any problem is fixed by him extolling his virtues all over it. The fusions we saw were super rushed and shitty looking, and Blue and Yellow were really inconsistent.
In my opinion the real fault at the heart of the show is with Pink Diamond, but we just gloss over the fact that she plunged her entire race into war, let down and betrayed thousands of her people and then ran away without considering the responsibilities she was dumping onto someone else. But it's all fine because she was ~woke~ uwu.
I also absolutely cannot stand most of the characters. I know it's a kid's show, but that's no excuse. Lars and Sadie are terrible, Amethyst is useless and Connie's intelligence is defined purely by the plot. Pearl used to be interesting but now she's just a lesbian cheerleader and the rest of the crystal gems are just there to yell encouragement like the side characters in every shounen anime.
That being said, I am completely in love with White Diamond's character design and her voice actor is amazing. I saw a picture of her design online and was interested enough to watch the last episode despite not really caring about the show anymore. The animation in the confrontation between Steven and her was done absolutely beautifully from an animation and colour point of view- but of course that was due to James Baxter so we can't give Sugar too much credit. People were joking in the comments that the fusion scene had more frames than the rest of the show put together- but tbh the difference was no noticeable that it was almost jarring. Yet again, the best animation comes from an outside source (Mindful Education). The music was also as great as ever, I think Sugar really has a gift for putting together soundtracks. I wish we had more of White diamond and saw more of Homeworld, but I get a feeling that we aren't going to be seeing much more of that.