What happens when an Internet-heavy game, such as Switch Sports, loses its connectivity and most of its player base after a few years?

It dies

There’s actually a channel I’ve been following on YouTube that covers dead online games (https://youtube.com/@RyeGamesOfficial?si=IR7AL-ZcQFCynoWO). It’s actually interesting because many of them will have a small dedicated player base of veterans, but otherwise, they usually just get forgotten.

Dang you had to remind me about that game. I had been missing wii sports for years and was hyped for the switch game when it was announced. Played the test days and it was fantastic, then it was released and I never managed to play with another human, ever. I would be fine with playing with bots only as well, but every time I tried to play I had to wait for several minutes while it tried to find someone for me to play with until a timeout was reached and a game started. I quickly grew tired of the wait and abandoned the game.

I guess that will be everybody's experience once the game loses connectivity.

This is a problem with every online only game. Publishers could push an update for offline play (I think switch sports already has this) or a way for users to host their own server. But when a game is at end of life there's no incentive to push an update like this. It needs to be considered while the game is in initial development. Usually the server shuts off and the game dies. See Killer Queen Black for one of many examples. That game got removed from the store too, so even if you buy a physical copy you can't update the software to the newest version.

It's sad.