As of ~1.20 the most overpowered mechanic in survival Minecraft is the villagers. You can easily create an iron farm, villager breeder, crop farm, and trading hub to get an infinite supply of iron, food, and diamond gear. This can be accomplished within the first few days in your world. You can see how in the video tutorial linked below. Here I have also documented the example villager breeder shown in the video to give a general idea how easy it is.
You can easily build a villager breeder that automatically generates infinite villagers as shown below. Be careful! If you leave them unattended for too long, you will be overrun by villagers!