Yes indeed, I don't see the need of mods in games like Quantum Break, Forza, Halo or Gears, actually I don't like mods at all since i think a game should be played like its designer meant it to be, and they also often ruin online competitive experience.
Regarding the other "limitations", borderless mode has not issues at all compared to full screen, actually it is better and i often used it in some PC games to get better frame rate, vsync always on works with Gsync monitors too so it's not a big issue either, also why would you turn it off causing frame rate fluctuation and screen tearing?
The only real limitation i see there is the lack of Sli support, which would bother people who have two GPUs and would like to run the game at higher resolutions using that combined power, though that's just a niche of the PC players, who usually have a single GPU, and i expect Microsoft to address this issue soon, Phil Spencer already tweeted about being working to add those features on Windows 10 game