"Marketing research." Some people have a singular, skewed version of success. Someone tell them that on itch.io we succeed together. Any money earned is a side effect. Those who disagree, good luck on Steam, too. The two aren't in competition.
Another common theme in articles by such people is that, after analyzing several successful games, they offer advice to developers on how to succeed or follow the trend in their games, but the video game industry is very complex and unpredictable. It may work today, but it won't tomorrow.