Until next year, the Xbox One is still inferior to its close rival, Playstation 4, in terms of resolution and game performance but with the arrival of DirectX 12, the console should be able to catch up although the graphics card is still using DirectX 11 technology. Maybe the graphics card should have the backported features of DirectX 12 for better performance and graphics but it doesn't seem to help out alot until the REAL DirectX 12 graphics card is out in the future. I don't know if you can replace the current graphics card with the DirectX 12 one for Xbox One but it is already possible for the desktop computers in the future. OK, you don't need to upgrade the graphics card hardware for Xbox One, Windows Phones and Windows tablets to get superior grahpics. You just need to do the software update of DirectX and that's it.
Downside though, only DirectX 12 games will make use of DirectX 12 graphics cards and the worse thing is that there will be heating issues for DirectX 11 graphics card. That is going to be a common downside and issue for devices using DirectX 11 graphics card and even Xbox One will be the included as the same victim too. Maybe next year, there should be a new Xbox One model with the DirectX 12 graphics card to fix this issue and get better performance.