Just to add to that, I also think those labels that are currently given, aren’t really sufficiently broad enough, with the problem collections I’ve made in the past, I would have trouble categorizing them with those current tags.
Which is why I still prefer the below alternative
Tactics, Tesuji, Strategy, Theory, Opening, Joseki, Fuseki, Attack, Defense,
Or even subgenres
Opening (Joseki, Fuseki)
Tactics (Honte, Proper, Common, Shape)
Technique (Tesuji, Haengma, Tsumego)
Strategy (Attacking, Defending, Invasion, Reduction, Theory)
Endgame (Counting, Calculation)
Miscellaneous (Assorted, Untagged)
Those should be robust enough to categorize most problems, I mean, the current tags of “Elementary” and “Best Move” could refer to literally almost anything, so if you wanted to learn a specific idea with those it’s going to be nightmare to sort through until you get anything nearing what you want.
The other side to things is that, the vast majority of problems right now are just tsumego related, and people tend to go outside the box when they are presented with clear examples, and to put a name on things. Until it becomes easy to navigate and show that a problem can be more than just tsumego, we won’t be getting many middlegame or specific problems. There are vastly more ideas and concepts in go than just tsumego, we should really be thinking of these problems as a (superior) interactive alternative to books when it comes to learning the game.