They don't violate licenses otherwise they would have been blown out of existence a long time ago, drown lawsuit after lawsuit.

The ones that Microsoft Apple and Google pay for, the codec licenses. FFmpeg believes that only end users need licenses for codecs, which is not only their belief, but it’s not a belief of Microsoft, Apple and Google, and it is true the sense of the status quo, but also, LGPL violations are a status quo. So you can see how it’s a bad idea for FFmpeg to make a stink about licenses.