I hate how console warriory this sounds, but is the general Xbox consumer base really all that interested in exclusives outside the trifecta of Halo, Gears and Forza?
For full context, my personal experience with Xbox is limited. I owned a XBO for a number of years before trading it in for a Switch, but otherwise have never owned a MS console. That said, the impression I've always had was that Xbox exclusives outside Halo/Gears/Forza tend to only be moderately successful at best.
Off memory, Blue Dragon, Phantom Dust, Sunset Overdrive and ReCore were all exclusives that just came and went. Tomb Raider was a launch exclusive and notoriously underperformed. The only non trinity exclusives I know of that even got a sequel are Mass Effect and Titanfall, and both got sequels that came out on other consoles. I will grant that the ME franchise was strongly associated with the 360 and did very well on that platform, but that's the only one I'm aware of that found success as a Xbox exclusive.