You wouldn't contain FFv1 in MP4, the only format incompetent enough for such corruption.
Apple has an interest against people using codecs that they get no fees from. And Apple don't have a lossless codec. So they don't offer lossless compressed video acceleration.
The idea is that when working as a part of a team, and you get handed a CG render, you can avoid sending a huge .tar or .zip file full of TIFF which you then decompress, or ProRes which loses quality, particularly when in a linear colorspace like ACEScg.