A Sony patent for a cartridge has been creating considerable speculation recently, with some believing the PlayStation 5 could come with a game cartridge slot while others opined the patent heralded the introduction of external SSDs for the next-gen console. However, it appears the device in the patent drawing is actually destined for use with Sony's Toio platform.
https://www.notebookcheck.net/PlayStation-5-game-cartridge-or-external-SSD-The-truth-can-now-be-revealed.443893.0.html
A PS5 is PS4 backward compatibility and it can play a 4K Blu-rays disc. So it should be a Blu-ray drive not a cartridge.