So here are some of the facts about Sword and Shield:
Half of the pokemon have been deleted
144 moves (more than just Z-moves) have been deleted, including a lot of classic and signature moves
Mega evolutions have been taken out
Trading costs extra now with a recurring fee
Version exclusives will now cost extra due to trading not being free
There are microtransactions in the games (the "Pay us extra money for Let's Go and you can get the gigantimax Pikachu! :)" and probably more since the digital preorders mention in-game purchases)
The game developers have directly stated in interviews that the games are the same exact length as old games, and leaks have shown this to be true with the same minuscule postgame like before. So any hope of a better postgame, one of the main things I have seen fans asking for all these years, has been dashed.
No noticeable improvements in animations or models. A ton of animations reused, including the dynamax and Pokemon Camp animations. It's yet to be seen if all of the models are new considering the old ones were future-proofed and look exactly the same as what's shown in Sword and Shield. There are still pivoting and T-posing models that are considered to be good enough "animations" for a $60 game. Models appear out of thin air. (And it's important to note here that the animation quality is what they claimed to focus on and got rid of half the pokemon for.)
Barely any graphical improvements, not enough for what is considered a triple-A game with a triple-A pricetag of $60 dollars. The graphics look like nothing compared to other Switch games and there was more of a graphical leap going from generation 5 to 6 and 6 to 7 than what they've shown for these games.
Even with HALF of the total pokemon in existence, less pokemon in the games than were in Pokemon Crystal a decade ago, they still made less than a 100 new pokemon, a third of the new pokemon just being Galarian and gigantimax forms, the latter you know are likely never to come back either since they've shown in generation 8 that they had no problem removing mega evolutions.
The majority of the pokemon who got those "special forms" were of course Kanto pokemon.
Dynamaxing is just mega evolutions, Z-moves, and totem pokemon combined yet it's being touted as a "new" feature and was added at the expense of all of the features it copies.
Pokemon Home is a one way trip meaning your pokemon are stuck there if they aren't in Sword and Shield. You better pray you don't accidentally send one of those Pokemon into Home because if Home is anything like Pokemon Bank, you'll be forced into a recurring payment for years just to keep your pokemon from being permanently deleted.
The latest interviews state that deleted pokemon MIGHT come back in future games. The quotes repeated the word "might" multiple times making sure we don't get our hopes up, meaning there's not even a guarantee that the pokemon they deleted will EVER come back.
Like previously stated, the games are 1.5× the price of old mainline games, meaning you are paying MORE money for less. We also know it's less since they already told us the games are the same length but half of the pokemon and a ton of other features/game elements have been deleted.
And these are all just a portion of the problems with Sword and Shield. The list goes on and on but these are some of the main problems. I haven't even mentioned yet how all of these problems are due to the Pokemon Company and Game Freak cutting corners, exploiting fans, and putting profits over everything else. They know that Pokemon sells no matter what, so why actually make something worth the price when you can just tape something together, slap on the Pokemon brand, and add a price tag? If anything, this whole fiasco has proved to them that they have die hard fans who will eat up whatever they make, regardless of quality. You can find those fans in the notes of every personal post about Sword and Shield that mentions even an OUNCE of criticism for the multibillion dollar company, attempting to harass and intimidate fans who don't follow their philosophy.