> Microsoft can more easily collect and analyze usage data, helping them better understand how users interact with Outlook. This allows them to make improvements, troubleshoot issues, and tailor the product based on user behavior.

I truly doubt this.

The "new" outlook is so much worse than the real one. There doesn't seem to be any interest whatsoever in providing a good user experience. Until recently, if you started writing an email while connected, then jumped on a plane without connectivity and finished it, it would just disappear when you sent it. Apparently that has been solved but still many issues remain.

Microsoft clearly doesn't care how much we hate it. If they did they wouldn't have released a half finished product. Therefore metrics are not needed for improvement. So what is the real reason then? I think cloud lock-in and upselling. They already have all your emails even if you're not using their email services. They can easily provide an upgrade path in the future and then cross sell with the other stuff like OneDrive.

Creating dependency so the customer can't leave has always been their business model. Especially in enterprise, Microsoft keeps offering cheap alternatives for stuff we'd pay for separately. But in the end you're stuck in s swamp that sucks you in deeper and are unable to get out of. Also the quality is much worse than AAA solutions. But there always comes a manager who can't refuse the cost saving over a separate product.

Another reason is perhaps that they just want to sell your data. But that's not really Microsoft's MO. It's Google's.