RPCS3 requires access to the individual files and folders within a game to run it properly. If a game is stored in a proprietary "highly compressed" format, the emulator cannot read it natively. Supported Game Formats in RPCS3
Playing "highly compressed" games on RPCS3 typically refers to two different processes: decompressing external archives (like .7z or .zip) to make them playable, or using file-system-level compression to save disk space while keeping the games "live" for the emulator. How Compression Works for RPCS3 rpcs3 highly compressed games work
The RPCS3 team has stated (via GitHub issues #5421 and #10723) that native compression support is . Their reasoning: RPCS3 requires access to the individual files and