Remember that downloading games you do not own is illegal. ISOs should be used for personal backups of games you legally possess.
The original 480p resolution of the PS2 era looks dated on modern 4K TVs. The PS3 remaster renders natively at 720p (scalable to 1080p), with anisotropic filtering, anti-aliasing, and re-rendered lighting effects.
Download and install the latest official PS3 system software directly into RPCS3.
For the PlayStation 3, the game did receive a native disc-based retail release. Instead, Ubisoft released a high-definition remaster titled Beyond Good & Evil HD on the PlayStation Network (PSN) in 2011.
However, because Beyond Good & Evil HD was primarily a digital release on the PlayStation Network (PSN) via the PlayStation Store, its file structure behaves a bit differently than traditional disc-based games. Disc vs. PSN Formats on PS3