They're 100% free in the sense that they don't ship closed code, ever. That is the goal to attain. However, we're not there yet. For that, hardware needs to be open. Hardware can't be as easily be made by a group of volunteers as software. Like at all. To solve this 'transient' state, all popular distros allow adding some sort of 'nonfree' repo so that, you know, shit can work. For instance, you are free to install Debian and not enable the nonfree repo, which is not enabled by default. You are also free to wonder later why your webcam doesn't work, you can't print, your bluetooth headset won't pair and your fancy gaming GPU outputs 10 FPS @800x600.