When comparing changelings with no real utility, cheaper is always better, since their primary purpose is to fuel tribal support cards: Universal Automaton is way better than Chameleon Colossus, for example
In 1v1 formats when players have 20 life and aggro decks thrive, the risk of losing 3 life a turn adds up
You can Vibrance via evoke using two red mana to deal three damage to any target, or if you pay two green mana, you can search your deck for a basic land, reveal it, place it in your hand, and gain two life
His ability to directly reanimate permanents does give him explosive potential beyond the other delirium commanders I mentioned, making it easier to assemble winning combos
Shatter is, of course, a great thing to have as an option with it being amazing when good and dead much of the rest of the time