The reason is that I have not seen proper ramp payoffs and there are a lot of fixing options that also advance the board state
If a permanent becomes a copy of a suspected creature, it won't be suspected
Not only does this mean that your Humans can deal damage to a defensive player by simply attacking another opponent, but if the chosen player is attacked, they effectively sustain twice as much damage
Voltron decks follow the same analogy where you usually want to suit up your commander to become an almost unstoppable threat that can finish the game on its own
I like that almost every new Magic set seems to have a three-mana counterspell with some gimmick attached
Ixhel, Scion of Atraxa Ixhel, Scion of Atraxa isnt only a reliable way to give players poison counters, it also has a very powerful ability once those counters start to stack up on your opponents