Legitimate emulation projects, such as RPCS3, have spent over a decade reverse-engineering this architecture. They operate as open-source projects, with transparent development logs and community support. In stark contrast, "ESX-PS3" emerged in the mid-2010s as a closed-source, proprietary project. For years, the developers of ESX claimed to have achieved a level of optimization and compatibility that rivaled or exceeded open-source competitors, often boasting high compatibility rates and low system requirements. Version 2.4.1 represents one of the iterations of this software that circulated on various download portals.
RPCS3 is on version 0.0.xx (still in development). A jump to "2.4.1" suggests fake versioning to appear more mature. No credible changelog exists for ESX versions.
Download the official PS3 System Software from the PlayStation Support site and install it via File > Install Firmware in RPCS3 .