This post is really eye-opening and shows a lot of why New Horizons feels kind of middling to me. The problem with Nintendo's "release game as minimal viable product then add content progressively" tactic that they've used since Splatoon is that when something like, say, a global pandemic, makes development harder, a lot of intended features are delayed. My hope is that they are indeed delayed and not fully cancelled, because the game as-is is far more anemic than New Leaf was
That list is pretty misleading though.
Lots of that functionality isn't gone, just repurposed.
The Roost and Brewster. - Actually missing
Gyroids. - Actually missing
Club LOL with Dr. Shrunk. - NPC gone, purpose of Club changed to receiving reactions from villagers, K.K. Plays at the plaza instead.
Re-Tail with Reese and Cyrus. - No point in having NPCs to recolour items when you can do it anywhere as part of the crafting system. You also never needed them to sell items to visitors to your island...
Villagers visiting houses. - Actually missing
Gems. - Technically missing but replaced by a vast wider range of crafting materials and a much expanded crafting system.
Tortimer Island. - You can visit many more island designs in this game than in NL, they just don't call them tortimer island...
Minigames. -- Actually missing, and these are the one part of tortimer island that is missing.
Events that aren't just boring holidays. - Uh, Animal crossing events have always been 'boring' holidays.
Missing fruits. - Tropical fruits are still missing, yes. They'll probably come...eventually. But this is hardly a big thing.
RV Site. - Replaced by combination of buildable campsite, the NPC from the RV site starting his own photo island, and the system where you earn points became the nook miles.
TONS OF MISSING FURNITURE SETS. -Can't argue this one.
Missing Nook's Cranny upgrades. - The problem here is the amount of items on sale started out way higher than in previous games. They could have artificially limited the initial store size to give more upgrades... but is that seriously a thing you want?
To compare the starting stores: New Leaf has, 2 tools, 2 furniture, 1 stationary, 1 wrapping paper and a fortune cookie.
After 1 upgrade NL has: 3x tools, 3x furniture, 1x carpets, 1x wallpaper, 2x fortune cookie, 1x stationary/wrapping paper/medicine.
After 2 upgrades NL has: 3x tools, 3x furniture (floor), 1x furniture(wall), 2x carpets , 2x wallpapers, 2x fortune cookie, 2x stationary, 1x wrapping paper/medicine.
After 3 upgrades: 3x tools, 4x furniture (floor), 1x furniture(wall), 2x carpets, 2x wallpapers, 2x fortune cookies, 2x stationary, and one k.k slider song.
Meanwhile: The starting store in new horizons has: all flimsy tools, plus slingshot, an umbrella, wet suit, wrapping paper, 4x wallpapers, 4x carpets, 2 limited furniture items and 2 unlimited items. Also some DIY recipes. The k.k. slider songs are sold too, but through the nook atm thing.
the starting point of the NH store immediately being somewhere around the NL store with 2/3 upgrades already applied (and so only one more to come) seems to have gone way over a lot of peoples heads. You can't even buy wallpaper or carpets without any upgrades in new leaf!
Villagers with dialogue actually worth something. - This is the worst mistake in NH.
Most of the shops in general (most got relegated to just randomly appearing in the plaza). - Shops being shuffled around isn't less content. At this point the only one with functionality missing from the game is the coffee shop.
Half the NPCs - Can't argue that.
Fortune Cookies - This is the same point as Nintendo items being held back below...
Museum Renting Rooms - Replaced because you can build anywhere.
Museum Shop. - Celeste got a new job in astronomy, having a separate store in the museum doesn't actually add much of value.
The Megaphone. - There's no microphone on switch, they couldn't have brought this over even if they wanted to...
Nintendo Villagers - Yeah, this sucks.
Nintendo Items - Actually missing, but missing furniture is already up above.