Outliners are great and underrated tools. But after a detailed analysis of Org Mode (and some other tools) I implemented https://github.com/rochus-keller/CrossLine which I'm using every day since ten years.
Org gained new features too in the last ten years. E.g. for crosslinking there is org roam: https://github.com/org-roam/org-roam
EDIT: of course there are many features which also Org Mode has, e.g. extremely efficient to operate by keyboard (for a trained user), multiple outlines, titles, attributes, not wasting screen space with menu bars and the like, just to name a few.
Org-drill is technically good for this, but ask yourself - when do you actually sit down and revise something? At your desk? In public transport? In the toilet?
If like me the answer is the last two, then stick with Anki. Much more portable.