BotW and Mario Oddyssey look the way they do because they were developed by teams who had decades worth of experience in 3D games, while Game Freak only started developing fully 3D titles in 2013, on a handheld console, which can't keep up with home consoles.
Even SwSh were developed with the Switch's portable mode in mind.
Mario and Zelda did a much better job of transitioning to console (modern 3D consoles, when they made the jump from SNES to N64) than Pokemon did with SwSh because they actually took their time to take advantage of the hardware. Their experience has little to do with it. And if they were that inexperienced that they couldn't handle it themselves, they should've gotten help from someone that actually knows what they're doing.
And it's bold of you all to expect Game Freak's first game of that magnitudo to be a masterpiece, have you learned nothing from the previous Gens?
Gen 4 is bad compared to Gen 5
Gen 6 is bad compared to Gen 7
If you want a Pokémon game with Witcher 3-level graphics or whatever, wait until Gen 9 or 10.
This is subjective, and I happen to disagree with that. 5th gen dumbed down the gameplay in a lot of areas (the region design got more linear, the trainer rosters were nerfed so most trainers didn't have more than 3 Pokemon, the game got a lot more handholdy with NPCs interrupting you all of the time). 7th gen also made the handholding worse and made the online worse. It's not just about the graphics, it's the full package, the gameplay, the level design, the story, the extra content, etc. And while the games have gradually improved in graphics, they haven't done in the same in other areas of the game and in fact have even regressed in some areas.
I love BOTW but to call it ambitious is always weird since it still suffers with a ton of empty space even when you factor Hyrule being torn apart.
Well if they filled that entire area it'd take them like, 15 years to make it or something. I think they can be forgiven for a game that incomprehensibly huge having empty space. For them to even be capable of making the game as big as it was is quite a feat.
And it isn't like it was the first open world Zelda either as even the first game did it.
The first game was much, much smaller than BotW and didn't have nearly as much to do. BotW's design is certainly inspired by the first game, but it's infinitely larger and more complex so to write off BotW because it's a similar design is laughable. It's like saying a cruise ship isn't impressive because it's like a rowboat.