We’d likely need a comprehensive study on it tbh. We don’t know how many would switch pace and become productive or just simply find another kind of hobby like television, books/comics, pen and paper RPGs and the like or go to things like competitive sports, etc.
Although I feel that there would be a net positive in the end.
Looking into this further, some of the technologies that exist right now (high end GFX hardware, CGI technology, virtual reality, 3d rendering, etc) that have a lot of use in our real lives were either thought of or partially funded by video games.
So now that I think about it more, we may owe video games more than we think.