I believe that one valuable way to approach this topic is to look at "under what conditions" is each extreme most useful.
With an eye toward balance:
You use Mitosis and Butterfly Effect as having strict guidlines to their usage.
A major reason for this is that their effects (or combos made from their effects) could have a powerful and impact on the meta-game, and so it is necessary to limit their applicability in order to keep them balanced. Imagine mitotic cata-titan... Or in the case of B.E. it could be to keep it from overshadowing other cards (why would you want to use deflag or pulverizer if you could just pop this butterfly effect onto any creature you want instead)
Cards with low key effects, on the other hand, can be made more useful if they are very flexible. Gravity pull, as a defense, requires a creature with high HP. As an offense, it requires diverting damage that could later be the difference between winning and losing… In either case, there are a number of other options. Its versatility, however, make it a valuable card because it can adapt to allow for adaptation.
Similarly, cards that have one primary use (precog.) are only viable if that one use can provide a benefit for a wide array deck types.
E.g. precog is a card of choice for rush decks. Narrow use, but that one use is a powerful feature that can support an entire deck archtype.
Rage potion, on the other hand, is a versatile CC and attack buff card. However, if it were limited in its usage to either just CC or just an attack buff, it would not stand out from other CC and buff cards.
So:
-If a card has a very powerful or impactful effect, it should have a restricted use.
-If a card's effect is very low key, or if there are other means available to accomplish one or more of its functions, then it should be left with a flexible usage so that it can remain useful and stand out as a card.
Finally, there is a balancing act to be done in both extremes.
-If a card is meant to be useable in any / every deck, its effect must be correspondingly low key. Thus one will run the risk of making it UP and impotent.
-Cards that have a very powerful effect must be restricted in their use to maintain balance. This is also important to prevent abuse in specific combos. Unfortunately, limiting a card's usage too much may end up making it "situational"
Finally, balancing cost - versatility and power is just one aspect of design… Thematics is also very important.
So another way to look at it is this:
-What elements tend to favor mechanics and cards that are powerful, but limited?
-What elements favor mechanics and cards that are subtle yet broad reaching and versatile?
-What elements lend themselves well to both?
