@LunarEclipsa I think there’s a reasons as to why Star vs. made shipping far more appealing than other cartoons: it actually developed the relationships. Think about other canon pairings in cartoons. Jimmy and Cindy, Kim and Ron, Danny and Sam, Phineas and Isabella, Aang and Katara, Chowder and Panini, Gumball and Penny, etc. The status quo of these pairings was established early in the series, and they never really changed that until the very end. Occasionally the shows would present alternatives, but they were always superficially nice, superficially attractive, and/or superficially assholes, and even if they paired up with a main character or his/her love interest, it usually only lasted an episode. Star vs. was never like that. From Season 2 onward, Star and Marco began constantly falling in and out of love with each other, thereby frequently changing the status quo. And aside from Oskar, all of the alternatives presented (namely Jackie, Tom, and Kelly) were all well-rounded characters that had actual depth to them rather than being stereotypes. These characters were actual alternatives that lasted for multiple episodes apiece, and Star and Marco even accepted this despite occasionally getting jealous (unlike other cartoon characters, who basically become SOLELY jealous). In short, we really couldn’t tell what couple would be endgame until the last stretch of episodes, keeping fans on their toes and actively engaging them in the shipping rather than it being a backdrop that everyone knows will end a specific way.
@Anonymius I’d like to add on to your points about why Starco became canon towards the end rather than earlier or at the end, and why being unpredictable doesn’t necessarily work. On the first, I agree that that helps to add to the potential tragedy of the ending, splitting them apart just after they got together, which would be lost if you had it happen as the closing shot. I also think it’s the only natural progression for the two. The show, at its core, has always been about Star and Marco, so however the show ended it would have to be in a way that develops their relationship beyond what it was at beforehand. You can’t regress their relationship or split them apart because they’ve already done that - TWICE - and both were season finales. And they’ve been best friends since the beginning, so you can’t really progress their relationship on the platonic scale. Going off of this, there’s no real good place to put it otherwise. If you did it earlier, it would ruin that further development because it would have already happened (unless Star proposed to Marco or something, lol), and besides, none of the episodes were ideal places to do it. Doing it in “Lint Catcher” would be very early on and basically retire the plot line long before it can become interesting, and would also sacrifice Tom’s development. Doing it around “Divide” or”Conquer” would look bad on Star and Marco in light of “Booth Buddies”, while doing it in “Lake House Fever” would look bad on Tom for the same reason. And if you did it in “Curse Of the Blood Moon”, that would cave into the fatalistic aspect that no one ever liked. If I could change anything, I would maybe have Tom break up with Star in “Doop-Doop” rather than “Sad Teen Hotline”, just so Star doesn’t go for her soulmate the DAY after breaking up with her previous boo, but I would still have the resolution happen in “Here to Help”.
As for the unpredictable part, I’d just like to provide some evidence to that. Adventure Time, Regular Show, and The Legend Of Korra all tried unpredictable pairings with the main characters. Adventure Time gave Finn a harem far larger than Marco’s, but ended up not pairing him with anyone. Regular Show gave Mordecai a few love interests but ditched them all and had him settle for a character who never spoke once or appeared before the finale. And The Legend Of Korra, after also having characters falling in and out of love, had Korra settle with an established character, albeit one that no one was expecting, and was considered ahead of its time due to it being a lesbian pairing. All of these were done in part to throw off the audience, and all of these were met with... mixed results to say the least.
@Geobukseon I dunno. While Starco might be the closest equivalent we have to a Ross-Rachel relationship in cartoons, I actually saw the exact opposite problem that you have. After “Curse Of the Blood Moon”, the writers seemed very determined to keep us in the dark as to whether or not Star and Marco still liked each other that it may have sacrificed the reveal’s impact later on. Up until the end there are basically no episodes where Star and Marco are made the center of things, aside from “The Knight Shift” (which can still be taken platonically if it weren’t for the last shot), so it comes as a slight surprise when they shift into full Starco mode. Granted, there are incredibly subtle hints that Star still loves Marco (the entirety of “The Knight Shift”, her missed hug in “Doop-Doop”, and her reacting with understanding in “Sad Teen Hotline” when Tom lightly suggested that she get with Marco), but again, they’re subtle. And while I knew that “Curse Of the Blood Moon” was a red herring of some kind, I didn’t really become convinced that Starco would be canon until Jackie’s comment in “Britta’s Tacos”. All this is to say that shipping wasn’t even a major backdrop of Season 4 until the homestretch. Of the last episodes (“Sad Teen Hotline” onwards), “Sad Teen Hotline”, “Here to Help”, and “Cleaved” were the only ones where shipping took center stage. Meanwhile, “Ready, Aim, Fire” and “Pizza Party” had no shipping whatsoever, and “Jannanigans”, “Mama Star”, “The Right Way”, and “The Tavern at the End Of the Multiverse” only had a brief (albeit pivotal) scene each. If I were to change anything, it would be to remove the He subtlety almost entirely. Had they added Moreno scenes of awkwardness and tenderness (like in “Divide” and “Conquer” respectively), made their feelings known to the audience at the end of “Curse of the Blood Moon” (instead of having Janna make Horcruxes for no apparent reason), add more romantic undertones to “The Knight Shift”, “Queen-Napped”, and “Beach Day”, and maybe even have Marco be the one to end the racism in “Cornonation” rather than have him and Tom be comic relief before giving it to Buff Frog and his children (playing into Star’s decision in “Doop-Doop”), I think people would be more accepting of the canonicity.