Netflix used to be superior in its selection, but when their deal with CW (inc. Warner Bros.) expired in early 2016, their inventory was drastically curtailed. One day, I went to my Netflix queue and more than half of my selections were no longer available.
Since I already had Amazon Prime (I live in a rural location and mail order lots of items), I just dropped Netflix.
Maybe Netflix has renewed their deal with CW, don’t know - but I’m happy enough with Amazon Prime.
For more recent releases and some that Amazon doesn’t carry, I just do pay per view through Vudu.
The Netflix interface was superior to Amazon. Quite often with Amazon, the streaming is not high quality (even though it’s supposed to be HD). I never had that problem with Netflix.
Often, I opt for slow Amazon delivery to receive credit toward digital items. This adds up, so I can get episodes of series like House of Cards for free.