Joy-Con drift that affected the originals immediately upon release. A bit less noticeable is that one unique characteristic from the original Joy-Con is absent in the new versions: an IR motion camera.
When the original Nintendo Switch debuted, the Joy-Con were remarkable gadgets due to their engaging haptic feedback (referred to as HD rumble), among other capabilities you might not have been aware of. One of these was an IR motion camera, positioned at the bottom of the right Joy-Con, capable of tracking movement, shape, and distance. This feature held great promise, but apart from Nintendo Labo, only a limited number of games actually utilized it. Therefore, it isn’t surprising that the IR camera didn’t arrive with the Joy-Con 2, but it does imply that certain games remain unplayable unless you retain your old controllers.