To me it seems like they don’t develop any particularly incredible tech besides streaming and storage

Well they pretty much single-handedly started the whole streaming on demand service for movies and series and rapidly grew accordingly. This success even allowed them to get into the production side of the movie and series industry. They also destroyed the DVD market and stagnated the Blueray market on their own.

Now they face more and more competitions after the other companies saw that there’s a lot of money in this. The lose of that monopoly of course impacts their success and they seem to struggle with it. But they still are a giant in that market segment. So it’s not surprising that they still are counted as a FAANG company.