While I enjoyed the game myself, I DO NOT recommend the product to anyone that is an experienced player of the past generations or anyone that's looking for a game that is not only challenging, but also has decent graphics. Pokemon Sword and Pokemon Shield were a massive step down from Gen VII, which I thought was the worst generation until Gen VIII. Any sliver of a challenge has been removed from the game unless implemented by the player through removal of certain mechanics (i.e. items, limited amount of Pokemon, fewer trips to the Pokemon Center, etc.).
I will admit that I found the Wild Area to be an improvement from the past generations, but it was poorly executed by having muddy textures, lazy shadows, and nowhere to explore for yourself because everything is right there to look at. The area is a great concept, but it was obviously handled by the wrong people.
The removal of the National Dex is nothing to complain about as it was expected to happen at some point in time. However, the reason behind the removal is more than enough to tick someone off. If it wasn't Game Freak already being too lazy to finish their biggest game, then it was because they couldn't optimize Pokemon Sword and Shield so it could handle all the models.
Optimizing a game is very important when developing. The failure to do so in Pokemon Sword and Pokemon Shield is what hurt to play the most. The game couldn't handle a consistent 30 fps on a console several times more powerful than what Game Freak was already working with. Frame drops were most common in battles with Dynamax/Gigantamax Pokemon on the battlefield, but even then there were frame drops with the simplest of attacks and even basic movements. Just moving around in the world would cause a drop in performance, almost unbearable to look at.
Another issue that comes from the poor excuse for a game was the story. The story fails to be anything more than going from point A to point B. Most of the good part of the story, such as important Galar lore, were quickly forgotten about in favor of the Gym Challenge. The more important parts were handled by the Champion off screen while he tells the player to continue the Gym Challenge and not worry about a thing.
There are already several other problems I could type about, but I feel like most people aren't interested in what I have to say, so I'll leave it off here. Thanks for reading this far!