The 3DS added a lot of focus online while the DS and DSi had it more close to a gimmick, and most games on the 3DS did have online modes.
Online service for all games was terminated in 2014, so online play of DS and DSi games is done with private servers by the community and online forums to plan games.
At this stage yes, barely anyone plays as it is now a niche community of enthusiasts.
Mostly Pokemon Black 2, Pokemon HeartGold, Mario Kart DS, and WarioWare: D.Y.I…
There are many online games on DS and DSi. https://en.wikipedia.org/wiki/List_of_Nintendo_DS_Wi-Fi_Connection_games
The 3DS added a lot of focus online while the DS and DSi had it more close to a gimmick, and most games on the 3DS did have online modes.
Online service for all games was terminated in 2014, so online play of DS and DSi games is done with private servers by the community and online forums to plan games.
At this stage yes, barely anyone plays as it is now a niche community of enthusiasts.
Ah private servers, that makes sense. Pretty cool man. Enjoy