Big: they can't speak to some things without legal review because FAANG have IPR. This causes a lot of friction. You may simply never know really why apple dropped ZFS. You can ask over beers. Sometimes hints is as good as it gets.
Little: there might be a team of 4 people on tcp/ip and only 2 of them have something like "commit" rights. You sort of expect its 20 phd and a bank vault of gold, and it's two guys. Smart guys, good guys, but if they both come to IETF then you know the tcp/ip buglist isn't moving and there's a "fall under a bus" risk, England 1966 football squad on one airplane risk..
Apple invents stuff which surfaces later. Appletalk over twisted pair had device discovery almost perfect. Printers shouted "I'm here" and everyone heard. It's taken years to get zeroconf and auto discovery out into the world of gigabit networks.
Apple does things other people don't do. They did some stuff in parallel path fetching, using mobile and WiFi to maintain the upper layer fetch in agile ways which was beautiful. The spec was there.
I kinda still hate OS9 and like OSX because UNIX but I also have gears grinding on the apple filestore and resource/data fork mapping into Unix .dotfiles which seeds were laid in the old OS world.