One thing that I dont think people are aware is that Booking.com uses extensive A/B Testing in the development of the website. This gives us the website that is extremely efficient in getting bookings but full of dark patterns.
Why don't you think people are aware of this? Seems obvious that they do this because they know it increase sales. Not like it was made up as a nice consumer-friendly feature by one of their UX engineers.
I think the keyword there was "Extensive". Literally nothing can be pushed to production without being A/B tested.