Article length actually does matter IF you have a high percentage of your articles read.
For example, regardless of article length on this account, I average 50 to 60 percent read time of my articles.
So a 2 min article has an average read time of 1 min and a 9 min article has an average read time of 4:30 minutes.
So it makes much more sense for me to write longer pieces because four and a half minutes is more than 1 minute. But if you find that someone is only reading 2 minutes of your articles regardless of length you are better off writing 4 or 5-minute posts than longer pieces.
Other than that your experience mirrors mine to a tee. Like my second account almost doubled the earnings of my main account yesterday. One has 140 articles, the other less than 20.
It’s weird times ‘round these parts.