The Index controllers can do everything other controllers can do + extra stuff. If you play a game that doesn't have finger tracking, that just means you don't get finger tracking. But the controllers themselves work just fine.

There are some games that might not have a good set of bindings for the index controllers by default (something might be bound to "squeeze the grip" when it should be bound to the trigger, for example), but you just open the settings menu (inside VR), click "custom bindings", and then pick the most upvoted community made set of bindings and it just works. Takes a few seconds.