Nobody would ever confuse me for a Microsoft fan-boy, but I personally feel more comfortable with sharing telemetry data (which both Google and Microsoft collect) with a software and services company than an advertising company.
More than 80% of Google's revenue comes from advertising (source cited below).
The majority of Microsoft's revenue comes from cloud services, Office, and Windows.
But I understand Microsoft has a trust gap with many folks, based on their anti-OSS activity of the late 90's and early 00's, and I'm glad we are all free to choose.
The only major browser (by market share) that is truly open-source is still Mozilla Firefox.
source: https://www.cnbc.com/2021/05/18/how-does-google-make-money-a...
source: https://www.geekwire.com/2020/filing-shows-microsoft-really-...