How much more is there left to collect? They already own Outlook, Edge, Bing, One Drive,
Sharepoint, GitHub, LinkedIn, etc. Thanks to numerous dark patterns, Microsoft is already getting a ton of telemetry about everything users are doing. You have to fight the OS to not let OneDrive slurp up every byte of data.
The only avenue really free from their clutches is mobile, but this does nothing to alleviate that.
But that's the thing: they do not have the data on things and usage patterns that exist outside the Microsoft ecosystem and/or on-premises/private clouds, such as work done within Atlassian stack, ERPs, desktop software and so on.
The only avenue really free from their clutches is mobile, but this does nothing to alleviate that.