Because if they are just: Everyone gets a mana of their choice, everyone gains 3 life, and then their ultimate is everyone draws seven cards, then they may not be the most powerful cards ever
You need to be able to beat the common archetypes with any deck you are building and in order to beat the fast agro decks you typically need lots of cheap things to be playing so as to not get overrun too fast
And once it enters, it deals a lot of damage, so you can knock out some creatures, or a creature + planeswalker
When it comes to Alesha, Who Laughs at FateAlesha, Who Laughs at Fate, a single attack will allow you to bring back any creature with a mana value of three or less
The blue side of Izzet Treasure decks allows you to take advantage of the ramp Treasure provides to cast all your blue spells since that color normally is rather bad at ramping