It is kind of weird that we still have these discussions today. A game like Super Mario World got this perfect in 1990. You have a "main" path in the game which is doable for the majority of the players, and then you have optional objectives that are much harder.
In open world games either the developers can implement specific game modes, or the players can do that themselves if they want.
In open world games either the developers can implement specific game modes, or the players can do that themselves if they want.