well according to the article Google Store app numbers peaked in early 2018 so it might not be as unrepresentative as you think. Time is a zero sum game and there are only so many apps all of us can install no matter how enthusiastic we are.
I was curious about that so I followed through the link and saw there was a jump down of a million, and upon googling it, it seems that Google did a purge this spring. It doesn't have to do with users or developers but just Google doing a clean-up.
