If you play a lot of constructed Commander, these decks arent any more complicated than player constructed decks, but theres a lot of triggered/activated abilities, +1/+1 counters, and various mechanics from all over Magic inside them
Synergy is not required - just brute strength
Access to 6 of MTGs most iconic spells is incredibly powerful, and while only Braingeyser and Regrowth see consistent play in the format (though Black Lotus absolutely would if it was legal), Terror, Disenchant, and Shivan Dragon can all still be very handy
During each of your turns, you can play a land and cast a permanent spell of each permanent type from your graveyard
At higher values it can even function as a one-sided wrath, clearing the board while leaving yours intact