Sony constantly patches security vulnerabilities with new system software updates. The primary motivation for using a downgrade repack tool is to access homebrew capabilities.
You can only downgrade exactly one step backward to the version you were on right before your last update. downgrade tool ps4 repack
You write the newly patched dumps back to the PS4 chips using your hardware flasher. Once desoldered and reassembled, you boot the PS4 into Safe Mode and install the corresponding official Recovery firmware via a USB drive. Warning: Avoid Fake "Software-Only" Downgrade Repacks downgrade tool ps4 repack
Disclaimer: This overview is for educational purposes. Modifying console hardware and flashing firmware carries a high risk of permanently bricking your device. Phase 1: Hardware Preparation downgrade tool ps4 repack