Well, Sony contributes, but not as much as Netflix (mostly by paying for development, especially LLVM development)

Apple hired the founder of LLVM and paid him to work on LLVM.

LLVM is pretty important to FreeBSD.

Plenty of big companies contribute to BSD financially or let their devs commit code to BSD because maintaining your own fork is tedious work and the smaller your changes from the upstream source, the easier your life.