It's fairly well known that above the ~$100 price level, headphone sound quality differences mostly disappear once equalized properly [0]. The real test is not stock AirPods versus H9i (as done in the review), it's AirPods versus H9i once they're both equalized to a common frequency target. Otherwise you're testing the manufacturer's tuning as much as the actual quality of the hardware.
Certainly, there's something to be said for the manufacturer getting it right in the first place so you don't have to bother with EQ when listening on a mobile device, etc. But I think the following two points are likely true:
1) People will score the AirPods highly in subjective listening tests;
2) The performance in those listening tests has more to do with the frequency tuning of the AirPods than anything about its hardware, and you could get a virtually identical listening experience with a $100 to $200 pair of Sennheisers and an EQ app.
[0] See e.g. http://seanolive.blogspot.com/2017/02/twirt-337-predicting-h.... Sean Olive has a bunch of papers on this.