Sony (PlayStation store), Microsoft (Xbox store), and Valve (steam) all take 30%. No one can speak on what Nintendo takes due to NDA. Why are they never brought up?
Those stores can be abusing their monopoly position as well. Apple has the greatest sales of all of those stores though so it should rightly be targeted first. They flew under the radar for far too long. People are literally going back to using websites rather than apps because of their decision, but Apple even tried to kill progressive web apps recently - which are basically just shortcuts to websites on the Home Screen.
