Nothing; but PHP, in experienced hands, will be waaay more productive for small-to-medium things. One issue is that experienced hands are increasingly hard to come by. Truly big, complicated things, built by large teams or numbers of teams, teams with a lot of average brains or AIs trained on average brains, will be better off in something like Typescript/React. And everyone wants to work on the big complicated stuff. So the "modern frameworks" will continue to dominate while smaller, more niche shops will wonder why they waste their time.