Because when all abilities are roughly around the same power level every ability is satisfying, rather than just a handful abilities or tactics which are disproportionally powerful.
Absolutely false. Abilities are satisfying to use when they are actually satisfying to use, not when everything is crippled to the same lowest common denominator. It doesn't matter how balanced things are versus each other if they ALL feel like shit to use.
When we cast most magic in this game we feel painfully underwhelmed because most of it is some combination of too much AP, too little damage, too small of an AoE, too long of a cooldown, or friendly fire making it basically unusable outside of LW play. You could delete physical from the game, magic is the only thing left to use, and it would still feel like shit to use.
Perhaps you should consider the possibility that the average value of the ability already being at a level you are satisfied with is a possibility, making outliers in tone with the average has no bearing on the average being satisfying. We could set an arbitrary level of what we could consider satisfying DPAP, let's say Barrage with Elemental Arrows, it's 4AP for X amount of value. From here-on every ability will be balanced around the principle that every AP is worth 1\4th of an X.
You can change this X/4 to anything that is satisfactory to you, whether it is 1 damage at level 20, or 10 000 damage at level 1. Whichever you want to use as an example, whichever you think is personally satisfying. Unless you mean satisfaction can only come from comparative increased value. That X/4 is your bread and butter, but it is only satisfying to use an ability if its DPAP is above 1\4th of X. In which case I can but suggest that there has yet to be a nerfing of source abilities, which would be your source of such powerful DPAP abilities.
After all we are dealing in subjective and relational properties.