You can have a fast, high-quality PS2 game (4 GB CHD). You can have a fast, small PS2 game (50 MB, but zero cutscenes and blocky audio). You can have a small, high-quality game (GBA or N64 ROM). But you cannot have all three on a PS2 title.
Finding high-quality is a popular challenge for retro gamers using emulators like PCSX2 for PC or AetherSX2 for Android . While most standard PS2 titles range from 1GB to 4GB, specific compression techniques and certain niche titles make these ultra-low file sizes possible. The Reality of PS2 Game Compression ps2 games highly compressed under 50mb high quality