Mario Odyssey is so much better than Galaxy and the Galaxy HD thing proved it.
The only thing Mario 3D Collection proved is what we always knew all along: of the first three 3D Marios, Sunshine is the weakest.
Galaxy has nothing on hat jumping.
Hat Jumping is a FLUDD-like gimmick that was actually properly budgeted and not rushed out the door this time. It's a one-hit wonder that won't be returning in the next Mario game for obvious reasons: it's merely an extension of Mario's core platforming mechanics, not an inevitable path for the franchise.
Wrath was right about Mario Galaxy the whole time. It's a very rigid paint by the numbers linear platformer that takes away options.
Wrath always preferred pitting Galaxy 1 AND 2 against others in the franchise, and he preferred Galaxy 2. I'm not sure he'd prefer Odyssey over either. Don't put words in his mouth.
The ability to turn into Mario Odyssey's adds a whole new dimension.
The debate rages: is Mario World better for expanding the moveset with the cape, Yoshi, and alternate endings, or is Mario 3 better for its more focused approach on linear levels and powerups? While I prefer Mario World for nostalgic, aesthetic, and unexplanable reasons, in general I prefer my platformers to be in the latter category. YMMV.
Balloon World and online added tons of replay value to an already vast game.
A Miiverse-like gimmick that doesn't compare to the initial astonishment of Galaxy's Luigi New Game+.
Mario Galaxy put me to sleep in that collection.
Books put some people to sleep, but I still enjoy reading.
The idea that Odyssey isn't refreshing or does no new things with Mario is frankly bizarre. Also 3d Fury is extremely flawed although it has some good ideas.
By your own admission as well as that of the marketing (Directs/trailers/commercials), Odyssey's appeal versus Galaxy comes down to an expanded moveset (still lesser than Mario 64), a distaste for linear platforming levels (which is how Mario originally started, and how I prefer to platform, personally), and a readiness to accede timelessness in favor of newness.