I've often found the need to refer to Facebook, Apple, Google but excluding Amazon, Netflix, Microsoft (ie in the context specifically of consumer internet, mobile, social but not ecommerce, b2b or streaming), but have shied away from FAG. GAF ('gaffe') would be great, but not sure anyone would understand it.
Personally, the only thing I ever watch on Netflix now is the new Israeli TV stuff -- Fauda, Mossad 101, etc. I think this is one consequence of them shifting to being a "channel" with their own content (which I mostly don't care for).
Almost all my streaming is with Amazon Prime, which has a much bigger selection of content suited to my tastes.
Magna is also a clash, so I'm not sure what's the benefit there.
At least manga and mangoes are funny, magna seems just posh and insufferable (which if you ask the right people, is an accurate description of those companies)
In France it's GAFAM that is most used, which makes sense since Microsoft is way more influential on the tech scene than Netflix, which is just a content provider.
It's just because FANG (don't think Apple was originally part of it) was a list of fast-growing stocks, coined by none another than Mad Moneyman Jim Cramer