“special people”
I assume they mean experts in that specific field, i.e. people whose job it is to put on firework shows. It’s not that there’s one specific group of people who can buy a lot more, but that there are some things that we should only allow experts to buy.
AV1 is very efficient (around twice as good as h264), but a filesize that low was almost definitely because the default encoding settings were more conservative than the ones used to encode the blu-ray. The perceptual quality of that 1.5gb file will be noticeably lower than the 44gb one