LT;DR: I don't like this generation at all. The game lacks intrinsic rewards and a fulfilling sense of challenge. Instead, priority seems to go to boring story and characters.
NO SENSE OF ACCOMPLISHMENT
Pokemon Sword / Shield has subtracts so many good elements of gameplay that were present in previous versions and the overall experience suffers for it. The mandatory EXP Share is the most obvious example. It means I can use only one Pokemon from level 5 to level 60+ (and I did), and five other Pokemon in my roster level up to 60 for doing nothing. For me it feels like I only earned one Pokemon and was given five freebies. There's no training going on here.
NO TESTS OF SKILL
The trainer battles are generally easy and most trainers have only one Pokemon. The routes are not challenging or interesting to travel. The dungeons are incredibly short and simple. HMs are replaced with bike upgrades and it eliminates the experience of relying on your own Pokemon for exploration. All of these changes surely make the game easier to design for Gamefreak because they don't have to make complex dungeons or routes with hidden or difficult areas to access, puzzles, challenging gauntlets of trainer battles that slowly wear you down and some that are brick walls, or carefully design when and how to give the player access to certain TMs/HMs.
NOTHING IS EARNED
There's no difficulty spikes in this game to remind you to keep improving. New areas are not intimidating. You don't feel like you've conquered anything when you've finished a dungeon or a route. Reaching a new town should feel like a milestone, but it just feels like a pit stop. The game has so many infinitely respawning random items to find on the ground, you can farm money and so nothing feels precious. I literally didn't buy anything for the entire game. Money has no value. Purchasing decisions have no sense of risk or fulfillment. The choices I make when I spend money are meaningless. Resource management is just one less aspect or challenge in this game.
NO DANGER, NO MYSTERY
Team Yell makes me miss Team Rocket. I liked the idea of encountering actual criminals in my travels and knowing that I could defend myself with my very own Pokemon and that others couldn't. It made the world feel unsafe and feel like like a wilderness, and it made my efforts as a trainer that much more valuable. I liked that I was the one who ultimately stopped a criminal organization. It didn't just mean I was an excellent trainer, it meant I was a hero. I liked how Team Rocket didn't have a screwball philosophy to push either, they just wanted to steal powerful Pokemon and possibly take over the world. No preaching or pretentiousness involved like other Pokemon villains.
Pokemon that appear on the map means they're not hiding in tall grass. The hiding part is gone and so Pokemon are more mundane than ever. Trying to encounter a specific Pokemon doesn't require any effortful searching or patience. You can just see what Pokemon inhabit any route or dungeon, so there's nothing mysterious anymore about a new location. There's nothing special about rare Pokemon when you can just reset the spawned Pokemon by walking away a little bit then walking back. Also, most if not all Pokemon can be avoided so there's no danger anymore.
STORY AND CHARACTERS
The story and characters are boring and feel like a constant interruption. The cut scenes go on too long and I
just don't care. I wish I could skip all cut scenes. It feels like
padding. I hope they didn't spend time and money on these. The Pokemon experience I grew up with was about a single trainer (you) exploring the world and battling other trainers. A lot of the story and characters were something that took place in my imagination and that was part of the appeal. If you used your imagination when you played Pokemon as a kid, type F.
GRAPHICS / MUSIC
I don't care to complain about the graphics because
my preference for Pokemon graphics is Gen 2. The fact that they're
making a setting look like Britain doesn't stimulate me. Although the new Pokemon
designs generally look silly, lame, or boring. Just do a google image
search for original fan Pokemon designs and weep for Gamefreak artists. I
can't say the music is memorable in this game, so that sucks. I
remember the music in older Pokemon games and when I hear it it brings back satisfying memories. I think I muted this game and put something on in the background.
CHANGES I WOULD MAKE
Besides rectifying all the above complaints to make the game feel challenging, rewarding, and even dangerous and mysterious, I would also try to make Pokemon Version A and B different in a more substantial way. Traditionally, one version has these Pokemon and the other version has those Pokemon. Sword and Shield does something cool with version-specific gyms, not that I care. The biggest missed opportunity that I can see is to make two separate versions feel a bit more like two separate games. For version B, I would make the player start in a different town and have you work your way around the world and all the gyms in a different order. This would require redoing all the levels of all the Pokemon, money and item rewards, and probably some other complicated changes to balance Version B. If I can make two different yet satisfying versions, I think that would better justify the existence of two versions.
I would definitely outsource Pokemon designs and I would reduce the number of Pokemon in the game. I know that's a sticking point for Pokemon fans, but I think it has to happen sooner or later. 2,000 Pokemon is ridiculous and I suspect most people stick to their favorites anyway. I want to try to give people new favorites and I want to encourage them to learn new Pokemon, and I think learning brand new Pokemon is part of making the game have a sense of mystery again. In fact, I might try make a simple custom Pokemon for the starter. Instead of picking one of three Pokemon, you can pick your Pokemon's type, body plan, color palette, cry, move set, stats, and name it. I would keep the options simple. The rival would get a custom starter Pokemon which is suited to beat yours. The game would treat your custom Pokemon as rare but standard Pokemon. That would be the in-game explanation. There wouldn't be some whacky custom gene gimmick driving the story or anything. The purpose of this is just to give the player the ability to pick a starter that suits their play-style and preferences slightly more than choice 1, 2, or 3.
I think I would bring back the humbleness of a Pokemon scientist like Professor Oak who was just some plain looking guy in a very small town with no shops. The Pokemon professor should be someone who is studying Pokemon in an underfunded rinki-dink lab because Pokemon are mysterious and because the professor is someone with an intellectual curiosity, not because they're an eccentric animal loving hippy. They send children on Pokemon adventures to collect data because that's the best way the Professor can do their research.
I would simplify the story and characters. I don't think Pokemon needs depth or story, I think it's a distraction. Pokemon is a game you play by yourself but you discuss and share with others. I think that's where the story is. It's about sharing your experiences with your friends, talking about the rarest Pokemon, the luckiest wins, the closest loses, and the struggling with the hardest obstacles until you had a breakthrough. It's about comparing your same yet unique experiences. I do think Pokemon needs a good Rival character again who can make you think "I've got to beat that guy!
The items in these games have gotten so bloated and I would cut so much of it out. There's no need to have 500 items in your Pokemon game. I'm sure that's going to save a lot of development time and cost and make every item that is included feel more valuable for it.
