For the record, I do quite like the game. There's a simple thrill in simply moving with Mario, because of his particular weight, inertia, his moveset, and how you can master and manipulate them to your advantage around the levels. He, and the rest of the game, has so many great animations and sights and sounds. Just on a pure spectacle level, on a "oooh whats over here, whats over there" curiosity level, its almost pure in its video game appeal. The primordial, simple joy of grabbing a controller, and having your interactions give a surprising yet logical reaction on the screen. That is what enticed so many, including myself, to this hobby in the first place.
But I also think that Video games, GAMES, have rules. Structure. Parameters that are set, and thus challenges can be imposed. Dont go out of bounds, dont double dribble, dont get shot by this enemy, you only have these moves and this enemy has these moves, etc. Because Odyssey is so wide and ultimately shallow in its acquisition of objectives, its challenges are stretched thin(and thus the feeling of triumph of overcoming an obstacle), its requirements on the player at a much lower level, on a moment to moment basis, then even the easiest Mario game before it purely down to its open structure. By breaking free of the linear stages and progression, its also broken the traditional method of the developer taxing the player to understand and utilize specific mechanics in THIS particular stage or against THIS particular level. For many, this will be seen as a boon(exploration! Discovery! Free to go where I please!). For plenty others, this will be seen as an opportunity cost that wasn't in the franchise's favor.