Whenever a question about of one these types of games come up, I always ask the question: why is this better than Stardew Valley? Because for the most part, that game crushes competition in this genre. It's also a nice bonus that it's a fraction of the price, although that's not a huge differentiator for some.
 

I haven't played it either, but I think you (and I) are too goal-oriented to like the things that most people like about the game and its predecessors. If you're looking for something super relaxing, it might be a good choice, but I'd view it as a gamble.
 

It's time we stopped spraying the tired and unhelpful descriptor "game" over everything that moves. You might find this article helpful in making a decision:

https://www.gamesindustry.biz/articles/2020-03-27-animal-crossing-nintendo-opinion
 

That gamesindustry article is good: Rob Fahey is a good and knowledgable writer.

A personal perspective: my wife, who plays even more games than I do (and I play a lot) has become obsessed with Animal Crossing: New Horizon since it was released. Even the MMO we've been playing non-stop for the last four years has spent entire days unplayed, due to Animal Crossing.

Watching her play, it looks to me to be Stardew Valley minus the story - and as I thought the story of Stardew Valley was the weakest part and the part that made me stop playing eventually, I consider that an improvement. If you like Stardew Valley type games, you will love Animal Crossing. Honestly, I would be playing it too, but there's only one Switch in the house :) .
 

I assume you already played Stardew Valley.

Right?
 

Having seen a few hours of gameplay on Twitch I wont be buying it.

Stardew Valley seems like the better game and I already have that.
 

I played the Gamecube version a decent amount. It looks incredibly boring, but there was something really charming about it. I decided to build up our museum, so I spent most of my time digging for fossils. Whenever I would find a new one, the museum curator would get really excited and a new display would appear in the museum.

On AC vs SDV, Google spit this out and it sounds about right to me:

"The difference, though, is that Animal Crossing is a "shape your town" game with extra elements like fishing or collecting bugs, art and fossils for your museum, doing little meaningless tasks for villagers and getting rewarded. Stardew Valley has stuff like that, but it's more of a farming game."
 

My 13 year old daughter absolutely adores New Horizons.