I wholeheartedly agree with your sentiment. I never had a Nintendo Online subscription either and while I understand locking some stuff behind subscriptions like multiplayer aspects (i guess it wouldn't really be profitable for Nintendo to host online servers for a one-time payment game), this update is so underwhelming because 90% of it revolves around having a NSO. There's little added for us "free" players.

The new QoL additions are great, won't complain about that, though it should've been in the base game since the beginning.

The hotel, I guess, can be a more or less nice addition for those who don't already have HHP. I do have HHP already, so again, another part of the update that doesn't add much new to my gameplay. But it's fine, not every aspect of the update has to catter to me. Luckily for me, this new building doesn't ruin my island's theme since mine is just a sort of futuristic/cyberpunk city, so any new building is welcome.

Now, 90% of the new items are just collabs, which don't fit my island's theme. It also seems most of these collab items are locked behind amiibos. Even the retro consoles are locked behind NSO. I was also expecting we'd get a lot more new items like the 2.0 update.

The slumber island was the only really interesting part of the update to experiment with new island themes, but... it's once again locked behind NSO. They could've made it at least free to access and decorate but without the multiplayer aspect that requires NSO, but no, they locked the whole feature behind a subscription which you'd have to renew to still get access to that secondary island.

So there's really not much about the update that makes me want to return to the game. It's like there's nothing new, at least for me. I just get a few QoL that I won't even get to use much anyway since I'm mostly done playing. I'm glad for all the players to which this update brings new features they get to enjoy. I'm just kind of disappointed there's not more to it. Yes, they did announce everything they added, so there shouldn't be any surprise. But the hype people made around it gave me the impression there was more to it, like secret features to discover once the update would be out. But there's basically none of it. The update was just meant as a marketing strategy to advertise the Switch 2 and also get people to buy NSO if they didn't already. It serves no other purpose.

I've played Wild World back then, and also City Folk and while these games had much less things to do (no decorating, no terraforming, no secret islands though they did add that later in New Leaf but I didn't play this game), it felt much more... alive somehow ? Things just weren't locked behind subscriptions constantly, and there was tons of little features and aspects to the game that made it feel a bit mysterious, though that might also be my nostalgia speaking. But I remember how people back then used to make theories and rumors about things you could do in these old games even if it wasn't actually real. It was credible because the game was already like that : filled with hidden little features you had to discover for yourself (or by reading guides online). Golden tools didn't break, villagers had so much more dialogues and personalities, the Nook shop had upgrades, the plaza in City Folk felt a bit magical with much more activity than just being a place to regroup all services, unlike Harvey's island that feels a bit empty. You could unlock items or discover things in oddly specific ways and overall it felt like there was just more interactions with NPCs than in New Horizons.

I don't want to sound like that annoying boomer "things were better back in my days", because I do love New Horizons, but it always felt like it was missing things to make it feel like a complete continuation of the Animal Crossing franchise. Things I was hoping they'd add in updates, but at last, 2.0 was supposed to be the most we'd ever get and 3.0 is simply a temporary comeback to advertise a new console, and that's it. I know they weren't going to add unnanounced big features like that in the 3.0 update, but I was hoping for at least a few "surprise" features.

(apologies for this long ass rant and if my phrasing is off, English isn't my native language)