I love it. Absutely love it.
Way back when I was 12 or 13 years old, I played the original Pokemon Red/Blue on my Game Boy. I absolutely loved it. Then I went into High School and on to college and started a career, and I put video games down for 2 decades. Then at 36 years old, I decided to get a Switch and one of the first games I bought was Sword/Shield. I was surprised at how little the game had changed, and it was really great being able to jump right in where I left off and not feel like I had missed a whole lot.
But Legends:Arceus has blown all my expectations out of the water. It fixes a lot of the problems with the other games - it gives you a reason to catch more than just 1 of every type of Pokemon! I find I really enjoy the Effort Level systems simplicity. Even though there's no in-game battling against friends, I find I don't miss it much; Pokemon doesn't always need to be competitive.
My ONLY gripe is that the storyline is just a bit thin. The antagonists of the game aren't particularly strong or scary and I don't feel much drive to "defeat the evil". But from what I have read, this appears to be a common trend in later pokemon games.
But that said, I also don't feel this huge urge/rush to get to the finish either. I'm having an amazing time exploring all the regions of the game, and it has definitely made hunting pokemon more interactive than wandering in grass until the screen flickers.
Game Freak has now changed my expectations of what makes a "good" Pokemon game forever. They definitely worked hard on this one but they've also set the bar very high for themselves - I find myself feeling like this is how ALL Pokemon games should be!