Those third party apps are not enabled by default, won't modify their functionality without your permission, and two of the three are open source.
And for me it's not so much that I trust Microsoft less than any other company. It's that using their services require so much trust, yet they give so little trust in return.
"Show HN: Rem: Remember Everything (open source)", 196 comments, https://news.ycombinator.com/item?id=38787892
"I made an open source Windows app to rewind and search everything on screen", 166 comments, https://news.ycombinator.com/item?id=40105371
"Rewind: The Search Engine for Your Life", 92 comments, https://news.ycombinator.com/item?id=33421751