Are you referring to me with that Gamexplain stigma? Because I actually love them: I just know that they complained like crazy about Gloomy Gem Grotto and now it's been horribly gutted and dumbed down

But I only know about that because Gamexplain is my go to gaming news channel on Youtube
To be honest, Odyssey has been forcing me to rethink Yooka Laylee as well. Shockingly, I JUST finished watching that video before coming here! I guess what they said about the game prompted to visit the forum.
I think the transformations, overly large worlds, and arbitrary 25 pagies per world are the game's biggest offenders. There are other things, like general polish being bad (I sincerely think they should have delayed the game...) and charm missing throughout the game, despite some enjoyable jokes, but I think the biggest strikes for Yooka Laylee came from the first three things I mentioned above.
Now don't get me wrong: I love Yooka Laylee. I love it for what it is: the spiritual successor to Banjo Kazooie I have been waiting YEARS for. To me, it was like wandering the desert dehydrated and then someone offers their crab juice to you: in that moment, the crab juice is utterly wonderful. But Odyssey shows how much more Yooka Laylee could have been, and just by polish. The games - for me - compare this way: Odyssey was a complete labor of love resulting from culminating experiences of various Mario games, while Yooka Laylee was (maybe?) a labor of love by people who have been out of the business for a while, and were still getting their bearings.
I guess since we opened up with a big post, I won't try so hard to trim mine: Yooka Laylee suffers mostly from arbitrary "we have to do x because of y," while Odyssey proved that this isn't the case. I don't know that any of the Odyssey worlds have the same number of moons: Nintendo simply put all the moons they could think of for a given world, and when they ran out they essentially said "OK, guess we're done putting moons into that one." Moons ranged from laughably easy, to incredibly difficult. As a result, it was hard to feel like they were running out of ideas because moons could come from ANYWHERE and ANYTHING, which provided some of the fun.
In contrast, Yooka Laylee stuck to this idea that each world needs 25 pagies. Right off the bat, some of those 25 are earmarked, meaning you will be effectively doing the same thing over and over again.
1. The Ghost Writers
2. Rextro
3. Rextro High Score (Hated this)
4. Quills
5. Kartos
Already, one fifth of the pagies are used up on every world for these: you know they are coming, and it takes a big chunk out of the exploration theme. Then, these actual challenges range from frustrating to I WANT TO SEE REXTRO DIE in difficulty.
But, another problem is that within a single world, there were repeats! Or at least, pagies that - for me - were too similar to other pagies. You have two races with Nimble, two swamp platforming obstacles with your tongue, tons of slot machines, and so forth. With how homogeneous the worlds were aesthetically, this problem felt even worse. It honestly felt like they ran out of ideas, but needed to get to their magical 25 pagies number, and so that just started putting stuff in that was either ridiculous (You basically get 2 pagies for beating boss 2... and I just don't know why) or had already been done.
As for the size of the worlds, I'm a bit iffy here. I think a FAR bigger issue is how "samey" every part of every world looks. Imagine if New Donk City were three to five times as large as it currently is: it would be nearly impossible to find your way around with the combination of size and similar aesthetic. And at least you'd still have a map! The only map in Yooka Laylee is the one you make in your brain! Yooka Laylee has the problem of "sameness" in spades, and it made spending time in any given world that much worse. By the time I was done with any world, I was sick of it because I had been staring at the exact same stuff for hours. Banjo and Odyssey fix this with a greater variety of smaller worlds that aren't quite so big. I know Tooie has its haters and I'm not one of them, but I won't deny that Tooie suffered some of the large, super "same" issue as well.
I could go on and on, but I won't. In the end, I still love Yooka Laylee, but I'm starting to see that I don't have to drink crab juice now that I'm out of the desert: I can have sparkle water! (Odyssey reference). I used to hail Yooka Laylee - despite knowing its faults - as absolutely wonderful, because I thought everyone else had given up on this genre. But Odyssey... well, it has shown me wrong. I won't be forced to play linear platformers for the rest of my days, and as a result Yooka Laylee just isn't as wonderful. Do I still love the game? I think you'll always look back fondly at your first drink after spending to much time in the desert. But I can't defend it quite as well now that we have Odyssey. Is it still great in my mind for being a kickstarter, and not some major publisher like Nintendo's game? Absolutely. But that's quickly becoming all I can lean on for a defense.
Yooka Laylee's biggest problem? It came out too soon. Can you imagine if the game were still in development? What kinds of changes might have been done to it after seeing the masterpiece of Odyssey? Heck, even without Odyssey, extra game development could have been a huge help to Yooka Laylee.
I'm in the place now where I think "Playtonic needs to really polish up the Switch version or else the game actually might be in trouble." They have so much time to work on things right now while they deal with bugs... I just hope that's a big part of what they are doing.