Xbox started losing in the last few years of the 360 era when they shpuld be buying studios and creating exclusives. That terrible release of xbone was just the confirmation.
But yeah I can see it being more succesful nex gen if they are able to provide a better experience for the player. The combo backward compability + more power (true 4k at 60fps) + game pass + streaming will be really nice. But it will be nothing without quality exclusives.
Having halo on release will be big though if they can make it right.