A big part of Pokemon for me has always been the pokemon themselves. Every generation I am excited to see all the new pokemon added onto the ever expanding roster of pokemon. Seeing the number of pokemon available in Sword and Shield being cut down is extremely disheartening. I fear for the future of the pokemon that are cut out. I have never really transferred my pokemon up generations as I prefer to keep them on the game I got them on. Still even though I'll probably never use any of the pokemon not on the Galar dex due to not wanting to pay for switch online, it just feels like a slap to the face being told that you can't use some pokemon in SwiSh, and not making it clear if they will ever come back. I was really hyped for SwiSh until I heard about this. I can live with DLC adding them back in latter. If only rotating rosters of pokemon available in games now I will be able to get used to it, however it would give pokemon a tainted feeling for me. If they are going to cut out some pokemon completely forever, I just don't know but it would forever taint all future generations for me.
I like the wide variety there is for Pokemon. Manaphy and Cherrim, two of my favorites are very unlikely to be available the former due to being a mythical and the latter due to not being available in a non-national dex since the Sinnoh games and being rather forgotten. And many less popular pokemon I just generally like such as Megaium, Ariados, Magcargo and Shellos are being threatened.
As for the competitive battling aspect I don't really care if the ever increasing amount of pokemon makes the metagame stale. I know all of the battling mechanics, but next to nothing when it comes to applying them all together in the metagame. The most I've played competitively was in gen 6 when I played in OU with a gimmicky lv 1 Nosepass and Monotype with a normal type team on Showdown. Locally I usually dominate everyone due to being the only one with level 90 pokemon in a no restrictions battle at a causal pokemon gathering. I remember some of my recent battles being more evenly matched in gen 7, however I battled rather rarely with only 1 other person. More recently I've been doing a few random battles here and there on simulator and with some of the weirder other metagames out there. I find the chaos and variation in random battles fun so I am all in for more pokemon being added into the games.
As for the catch them all aspect. I have never really been into completing the pokedex. The first time I've ever completed a pokedex was in Moon, as the shiny charm for just the regional pokemon seemed worth it. While I play I tend to try to catch every pokemon I haven't gotten in the game yet, even though I can't be bothered to breed, trade and evolve pokemon to complete the pokedex. Still I feel like people are less upset about no longer being able to complete the national dex and more upset about no longer being able to use their favorites if they get excluded from the game.
And now some non removing part of the pokedex thoughts.
Wooloo: The body looks a little plain to me. Just the ball shape and those bare legs just make me feel like something is missing.
Gossifleur: For some reason Gossifleur reminds me of Flamberge from Kirby. I guess it has to do with the similar looking hair/petal styles. Still is it just me or does it's eyes look like it's staring creepily into your soul in it's official artwork?
Corviknight: Corviknight is awesome. I was amazed by it the second I saw it in the trailers. I am getting one on my team when I get the game.
Zacian: Never has a legendary be so majestic and so hilarious at the same time. I love how Zacian is literally carrying a sword. Now, if they can get the other half of fetch down.
Wild Areas: The open world looks amazing! From experiencing it from a mod it is very fun to explore the world, looking for new areas and pokemon. The mad dashes made when I thought I saw a pokemon I didn't have yet, especially when they were flying overhead and constantly checking my pokedex to see if I had the pokemon or not, fun times. GameFreak has the power to carefully craft the wild areas throughout the region and make them full of diverse pokemon and make them distinct and memorable from each other. This is the new feature I am probably the most excited for in SwiSh, please don't mess this up GameFreak.
Still Ive heard that you can wander out to find game breakingly powerful pokemon in these areas early in the game however not be able to catch them. I wonder what they will put in place to prevent someone from saving then constantly save scumming until they manage to catch a game breakingly powerful pokemon. So far the only thing I can think of is limiting them behind raid battles, but even then there is no one stopping someone from finding their 3 friends who already beat the game from assisting them in capturing a powerful pokemon early in the game.