Just like previously we used to have lots of jobs like HTML developer, JavaScript developer. But new frameworks like React made frontend development so easy it became a basic skills and jobs got reduced. Same thing with happen for AI it help making website faster and easier so one person can handle entire full stack development along with Devops. So yes number of jobs will reduce .
Or alternatively, more smaller companies, that couldn't afford to hire big software teams earlier, will now be able to hire a few developers to do the same work, and total number of jobs will increase
Never. It's there to help us and make our work faster.