I have seen this question before. The sentiment I see repeated often is "Do not get into making games from a drive to, or expectation of, making lots of money. Go for it if it is something you love doing."
Most of what I make comes from ads in a screensaver/wallpaper app I made early on for iOS. I do not make much. It is not amazing, but I think it gets used because there are fewer of that type of app available. Likewise, my most popular Android app is a live wallpaper (not in C2) that is Christian themed. It gets noticed because it is decent, but also because there are fewer of that type of app on the market. Putting something out there that deserves good reviews, and actually getting those reviews helps a ton.
As mentioned above, you get more out if you put more time into it. It helps if you are artistic or have access to someone who is. It helps if you know how to market/advertise and network.
Learning to write code, learning to work with others, and being a part of a larger community focused on app development have the potential to open doors to things beyond apps in Construct 2.