A moot point is a topic or issue that is no longer relevant, unnecessary, or has already been decided. It's often used to describe an argument or discussion that is pointless because it doesn't matter anymore or can't be changed.
It's a completely moot point for them to continue sticking their faces onto a work like the one above. (artfcity.com)
However, I think that's a pretty moot point when you consider the far superior way to get those same nutrients: eat whole vegetables and oranges. (fitwatch.com)
If you don't want that type of game you could simply go and play something else, I'm sorry but it's a completely moot point. (n4g.com)