Oblivion was never released on PlayStation 2. The PS2 hardware (32 MB RAM, 300 MHz EE, 4 MB VRAM) could not run the Gamebryo engine / Radiant AI / Havok physics at playable fidelity.
To Play Today: PC (Steam/GOG) + Unofficial Patch + Mods = definitive version. Xbox Series X|S = best plug-and-play console (60 fps, quick resume).