You see, that’s your problem. Companies don’t make games for any other reason than money. Since there are no microtransactions or subscriptions available, they quite frankly don’t care if you ever play the game after you’ve purchased it.
They moved a lot of units already and considering it’s only a side game with reused assets, they made a profit. Therefore, the game by all means is a success for them, even if nobody would play anymore.
Concurrent players also shouldn’t influcene future sales by much, since you only need 3 people at a time
Wouldn’t have expected anything else. The two types of people I’ve mostly seen buying the Switch 2 are those who are really into Mario Kart and those who are into Pokemon, for the extra frame rate.
Neither of these groups is known for buying 3rd party games - at least not the ones I know.