I have been thinking about how game companies design games with too much focus on particular things, often losing out in other important ways. Some examples:
In Skyrim, there are talent choices you can take that allow you to get critical hits. Crits do fixed amounts of damage in the neighborhood of 10. This is fine but not great when you get your first sword that does 25 damage in a swing, but becomes ridiculous when you fully upgrade and attack for 1000+ damage, with a chance to crit for 10 additional damage.
In Diablo 3 there is a talent called Gargantuan that summons a dork that blocks enemies and attacks them. It does about as much damage as your character can do spamming your best spells nonstop. In the endgame this ends up being okay because the extremely high powered sets make it possible to have builds with or without Gargantuan, but when levelling up it is ridiculous. How does it make any sense for me to be a caster when I can summon a random dude who does more damage by himself than my casting?
In DnD 5th edition there are a bunch of save or suck spells. One of them is Levitate, and it is a lot more powerful than the others because the enemy only gets a single save against it. However, when you are in a dungeon with a low ceiling Levitate often does nothing. But when you are outside, Levitate is regularly a save or die spell. You lift the enemy up, kill their friends, then leisurely shoot them with fire until they die. Balanced in a tiny hallway, ridiculous out of doors.
In Mass Effect 3, biotic explosions were based on the health of the enemy. They worked fine on lower difficulties, but on higher difficulties they were insane against the really high health enemies. They made other abilities with fixed damage ranges seem terrible.
There is no denying that it is hard to look at all of the possible situations a given ability can be used in and make them all balanced. Heck, perfect balance isn't even the goal as far as I am concerned - choosing Levitate when you are going to be fighting outdoors is an interesting tactical choice... we like those! The problem is when an ability is so out of whack in some situations that the gameplay becomes absurd if you don't make the 'correct' choice. Talents that have no measureable effect are not well designed. It is fine if they are niche, or largely there for flavour, but if all a talent is doing is pumping out numbers then it really needs to have numbers that work.
For example, there is a weapon in Diablo 3 that occasionally summons a bunch of cows with halberds to murder your enemies. The weapon is not good. It finds its way into zero endgame builds. However, that is fine because that weapon is fulfilling its role as giving people a few giggles when they equip it just to see what the heck it does. Nothing wrong with having some of those, in fact I quite like it when I game has that.
Similarly, there are talents like Angry Chicken that aren't good. But they don't have to be, because they turn you into a chicken, you run super fast, and then you blow people up. Badly. Which is okay, because you aren't using Angry Chicken to be good, you are using it to be a chicken. But when a talent like Gargantuan is so overpowered that you feel like an idiot for not using it, that is a problem.
When creating a mechanic all game designers should consider all of the ways in which it will be used. It is fine for a mechanic to be better in some circumstances, but it should do *something* in any circumstance where the player has reason to believe it will be effective. Games feel best, and have the biggest following, when there are choices to be made about numbers but those choices generally should jibe with the feel and the lore that the game has. When I am a summoner/nuker class, a single summon should not be more powerful than all my nukes combined. When a talent says that it makes a thing do more damage, that thing should do more damage in a noticeable way.
This sort of thing doesn't generally impact the super hardcore players very much as they will research the optimal builds and choices and go with them no matter how silly they seem. However, it has a huge effect on whether or not the average player enjoys the game and feels good about their choices in the game, and that is something that too often goes overlooked.