Why are people not able to scuba dive to the deepest parts of the ocean?

People cannot Scuba dive to the deepest parts of the ocean primarily due to extreme pressure, which increases by about one atmosphere for every 10 meters of depth. At depths beyond 40 meters, the pressure becomes dangerous for human bodies, causing potential physical harm and requiring specialized equipment. Additionally, the lack of light, frigid temperatures, and the absence of breathable air make deep-sea environments inhospitable for divers. As a result, exploration of these depths typically relies on submersibles and remotely operated vehicles.