Biomes are risk tiers. Each one raises loot quality and raises the danger in equal measure, so a move is a decision about what you can handle.
Forest and plains
The starting biomes. Safe, well supplied with basics, and the right place to spend the first week.
Desert, snow and burnt forest
Mid-tier biomes with better loot and nastier enemies. Each adds a survival pressure, such as temperature or tougher zombie types.
Wasteland
The endgame biome. Best loot in the game, constant danger, and no reason to be there before your gear is ready.