Say what you will about the relative differences between the Xbox One and the PlayStation 4 — in the long run, we'll look back at the two consoles as remarkably similar pieces of hardware.
What differentiates the two mainly is games: Sony simply has more major PS4 exclusive games than Microsoft. Whether you're talking about "Uncharted" or "Bloodborne" or "Spider-Man" or "God of War" or, well, the list could go on and on.
Microsoft has some biggies, like "Halo" and "Forza," but this generation of consoles was primarily led by Sony due to a consistent stream of excellent, exclusive games.
Things are clearly turning a corner in this regard: Microsoft has major entries in the "Halo" and "Gears of War" franchises in the works, while Sony is outright skipping E3 this year. Microsoft even went as far as to buy up a whole bunch of game studios which are presumably hard at work right now on new, exclusive Xbox games.
All of which is to say one crucially important thing: More than any other factor, Microsoft needs great games, and it needs them coming out at a steady cadence.
"Halo Infinite" coming to Microsoft's next Xbox might not hurt in this regard — at the very least it could offer a bridge between the Xbox One and whatever's next to dedicated fans, coming to both like "The Legend of Zelda: Breath of the Wild" did with the Nintendo Wii U and Switch.