I'm going to ignore the glaring Galar Dex issue for a second and focus on the "new" Pokemon. That's the biggest disappointment for me.
Grookey: another monkey Pokemon. We already have 17 monkey Pokemon including a pure Grass monkey line like Grookey....
Sobble: another amphibian Pokemon. We already have 17 amphibian Pokemon including Mudkip and Wooper which look the same as Sobble.
Gossifleur/Eldegoss: another cotton bloom Pokemon. We already have 19 feminine looking cotton/flower Pokemon! How is Eldegoss any different to Jumpluff and Whimsicott? And Gossifleur is just a Floette.
Drednaw: another turtle Pokemon. We already have 10 turtle Pokemon.
I'll let Yamper slide because you have to have dog/cat Pokemon. But Corviknight is just another Skarmory. Impidimp is just a poorly drawn, goofy looking Sableye.
Now let's look at their designs.... what is with all the HIDEOUS primary colours on everything? Did they just decide every Pokemon needs to be Red, Blue and Yellow? Seriously, because of their colours Gossifleur and Drednaw, as well as the two Wolf box legendaries, just look stupid. Whoever designed the Gen 8 Pokemon needs to be fired because wild flora and fauna are not all Red, Blue and Yellow!
If you go back and look at it, it becomes painfully obvious that they ran out of Pokemon ideas midway through designing Gen 5 and since then they're just recycling ideas.
We don't want ANOTHER cotton/turtle/amphibian/monkey/rabbit!
This is why people get super excited when the fake leaks come out and show us exciting new Pokemon. Just look at the fake leaks from the last couple of months: dolphin, manatee, flea, termite, mole rat, ghost clock, plague doctor, white tiger, trojan horse, metal snake, big tree, narwhal, bubonic rat, komodo dragon, cheetah, alpaca, hot pepper, dynamite, cutlery, water buffalo, beluga, new evolutions for old pokemon, bug/ice pokemon, new eeveelutions..... NEW AND EXCITING IDEAS!
And what did we get instead? Another friggin grass monkey, another girly cotton ball and another mudkip. Thanks Gamefreak. You're doing great, Sweetie, keep it up.