Usually I don't flatten the majority of the layers during the image creation and this is the record of turning them on ,in a certain order on my PSD file. Keeping a lot of layers could be messy indeed,but somehow I prefer to have a control on any single detail till the finishing of the artwork...Especially in case I need to go back to the artwork and fix something after a while,which happens very often.
In fact, it is always good to leave your work for a day, two or more, away from your eyes before posting it in social media and art forums - it will help you notice much easier any problems you are not turned. just because you've gotten used to them during the work process.