Hmmm. I was thinking about game history in terms of market trends and learned there's just zero sales data I can use to test hypotheses, haha.
Did Final Fantasy 15 sell more than Final Fantasy 8? Whoooo knows?
I was specifically interested in seeing of claims of a decline in the Japanese game industry (such as Keiji Inafune's "Japan is done" statement from 2009) is something backed up by sales numbers or just one of many different narratives you can construct by looking at the situation from different angles.
It's like 8.5 million (VIII as of Dec 2013) vs 8.1 million (XV as of Sep 2018) right now.
The question I was interested in is less trivial than this, I promise.