This hasn't been true for a while for certain applications under the right circumstances. There are architectural renderers, product renders and certain movie shots that will fool 99% of people into thinking they're looking at a photograph. Once motion is involved it gets much harder but there are still snippets of rendered video that could pass for real video.
It is true however that the problem is not fully solved in general. There are still things that are not handled very well in still renders and animation (particularly human animation) breaks down in more situations.
Watching the short "The Third & The Seventh"[0] was the last time I believed any photo or video of architecture to be real, and that was already 8 years ago!
It is true however that the problem is not fully solved in general. There are still things that are not handled very well in still renders and animation (particularly human animation) breaks down in more situations.