I think Medium has a ridiculous expected reading speed.
My leisurely, not rushed, not skimming reading speed is around 800 words a minute. The Medium algorithm might be deciding that I did not read many things, particularly if they are short.
I’m sure it’s quite true that the average adult reading speed is abysmal. I’d think that the number jumps much higher for people who read regularly and even higher if you counted serious writers.
Who is the average Medium reader? Are they someone who thinks reading a book a month is an incredible accomplishment or people like me who can read a book in a few hours if I want to? I would guess those readers lean toward the latter and some exceed it handily.