ROVs have already reduced the demand for commercial divers on some types of work. But it's going to take decades (if ever) until they're able to do the full range of human tasks. Some construction work has to be done essentially by feel in near-zero visibility so using an ROV for that would require advanced force feedback mechanisms, maybe imaging sonar and other sensors. Not necessarily impossible, but extraordinarily difficult and extremely expensive with current technology.

For sport and exploration divers, going there yourself is kind of the whole point. I'm not interested in watching a video feed from an underwater drone.