I remember when they got away from it. My pay started going downhill after that. It would also seem that system would be less susceptible to gaming. I honestly thought they got away from that formula for one with more smoke and mirrors to diminish writers' pay. Of course, I write satire so I tend to be cynical.
I was here just before they did the pay based on read time and actually wrote about how I liked that idea. https://medium.com/@larrylambert269/claps-vs-read-time-a-newbe-weighs-in-31ad737327f6
I was so young and naive then.