This is the most sought-after feature. Rebirthing typically wipes your base and inventory (except for Reborn-proof items) in exchange for powerful new gear. GUIs automate this by monitoring your current money and automatically triggering the rebirth once the target amount is met.
Most modern utility scripts for the game include a suite of automation tools: Miner's Haven GUI (Auto-Sacrifice, Auto-Rebirth...
A permanent, one-time decision per save file that reverts you to life 1 in exchange for advanced mechanics like Reborn Fusions. Scripts can automate the multiple verification clicks required to finalize a sacrifice. This is the most sought-after feature