The Mario games were originally made to have as little worldbuilding as possible to avoid the level of autism that Zelda games have with their timeline. And the origami bits bleeds into the princess transforming into an elemental animal, but that's only for bosses. Why they didn't keep it as an rechargeable special move is anyone's guess.
Historically speaking, Nintendo has several teams of programmers, along with several smaller companies to develop the games. The difference here is that Odyssey is made by Nintendo, which is easier to copyright and personalize the characters. Games like Paper Mario have an rep breathing down a company's neck to ensure that everything is kosher.
That really only mostly took off for every game after the original SMB1’s started flying off the shelves in terms of success. When Mario was still considered Mr. Nintendo internally, there wasn’t really any need to have Mario’s world on a leash since Nintendo’s big focus then was making “games” in the purest, toy-like sense. Donkey Kong and its original sequels, Mario Bros. Wrecking Crew was being worked on around the same time SMB1 was and the general plan was to have Mario work all sorts of fantastic jobs before Super Mario was spun off into its own coherent series.
A lot of the continuity and worldbuilding issues stem from Nintendo continually trying to play the nostalgia card and keep Mario’s old adventures (Donkey Kong included) relevant. What should be more accurate to say then is that Super Mario specifically was initially kept as fantastically varied as possible to open the room for series growth and creativity (following DDP/SMB2, characters started “leaking” between titles like SMB3, SMW, and Yoshi’s Island) and the actual character focuses and development were kept to a minimum. This is also why it’s difficult to work Super Mario around any sort of complex RPG plot, because you can’t really do much with Mario as a character, or other series mainstays, Peach and Bowser in particular.
A lot of the 00’s era Mario games were flexible enough to have elements of spinoffs appear in other spinoff titles like Wario getting continued spotlight after being introduced in SML2, NSMB overworld course tiles just being Mario Party coin spaces, Donkey Kong continuing to be relevant in spinoffs despite not being in a mainline game since. This is all worldbuilding. What you actually mean is that there isn’t any sort of continuity between the titles, to which I partially agree, if it weren’t for the fact that Origami King goes hard on the Bob-omb death thing, which should not only be a given in mainline Mario, but should be completely glossed over anyways if you’ve actually played a full mainline Mario game long enough.
My problem is this. Replace the Bob-omb with a Goomba. What changes? Nothing, right? By the game’s logic, Goombas are throwaway foot soldiers and they’re only good for stacking on top of each other in tower formation. Which is perfectly valid logic for a Mario game with zero stake or consequence, but if it were to play out, we’d get an overly long melodrama about Goombas being born to get stomped on, and they have a family and whatnot. I’m definitely sure this whole interpretation isn’t parodied and mocked relentlessly by “game humor funnies” on the Internet or anything, because it’s definitely A-class writing.
As for Olivia, I believe Tanabe reiterated it himself before, but he and Kudo were able to create OCs that were completely alien to the Mario world; what’s more, there’s not really any in-universe justification for the battle system either. Olivia only helps out if you ask her for advice (she’s a standby character akin to Navi) or if you land on a Vellumental Circle (the Vellumentals themselves depicted as fantastical beasts that will also probably not appear in any future capacity in the series, nor help justify the battle system further).
PM64 and TTYD were plays (TTYD’s being an in-universe theatre production). SPM was a Mario platformer (even though it should rightfully be a spinoff). Sticker Star used stickers, Color Splash used paint. Going off of this pattern and watching trailers I was expecting confetti to be used to craft weapons as well, but that’s just wrong. Equipment is just equipment, and play no role into the actual ring-turning. Though the ring battles do facilitate interesting scenarios, there’s nothing in the story that facilitates the ring battles themselves. There’s a ring battle puzzle simulator you can access, but there’s nothing else apart from that. It’s very “gamey” when it comes to its own logic. It’s what other people have said before; it’s a half-hearted attempt to implement what long-time series fans have been asking for, and it ends up feeling like an insult that doesn’t understand why these specific creative decisions were made.
