Microsoft is missing 2 key things
First party studios
Sony has Guerilla Games, Naughty Dog, Polyphonic, Sony Japan, Bend, Sucker Punch, Santa Monica, Media Molecule and partnerships with the likes of From Software and Quantic Dreams. Not only do Sony pump out their main IPs like Uncharted, but they allow their studios to grow and create new IPs, this is how good games like Uncharted were born in the first place. This generation we had Bloodborne and Horizon already. People hated on Guerilla after Killzone games were panned, but Sony gave invested into the studio and allowed them to create something new. Of course there have been misses with games like The Order. But we have had games like Until Dawn, Gravity Rush, The Last Guardian and Horizon which were all decent. Experimentation is good and allows new IPs to be born. Unfortunately MS didn't invest in first party studios, they wanted Bungie to make Halo forever and list out on one of the biggest IPs Destiny this gen as a exclusive. They canceled Scalebound and the games they released were substandard such as ReCore. Sunset Overdrive, Killer Instince and Quantum Break were a good start but they dropped off.
Japan Games
Sony gets free exclusives from Japan, with games like Yakuza and Nier. Unfortunately this is something MS can't really do anything about, they tried hard with 360 by investing into Japan, but the core userbase is the western audience.
Because of the above 2 things i don't think MS has a chance in hell to compete with Sony in terms of exclusives. They can announce the next Halo, Forza and even the expected Crackdown which supposed to release ages ago. Let's out things into perspective one E3 MS had a amazing E3 with Phil being one of us, and telling us it's about games. They showed Crackdown, ReCore, Halo, Forza, Scalebound, Phantom Dust, Fable Legends and etc. Halo released but didn't light the world on fire, Forza was great, Fable Legends, Scalebound, Phantom Dust all got canceled. And ReCore wasn't a good game. Looks like that E3 was a hustle and the reality is MS does not want to invest in first party games.