[mjevans]

They're successful mostly because (many) end users ignore patents; at least the ones that don't work at large companies with dedicated legal departments (and targets on their back because they have actual money).

Further, that's why Vorbis, VP9, AV1 etc, show less adoption, even though they're free, for end users the other formats have been baked into hardware that only works with the closed ecosystems and the average guy can ignore the patents and continue to work with that non-free ecosystem.