Edge has a feature where it will periodically pull the bookmarks and browsing history from any other browsers you have installed, so they'll then get sent to Microsoft and associated with your Microsoft account. This was initially enabled by default without the user's consent, although I believe now you may have to opt into it if you do a fresh Windows install. I only realized this was a thing because one time my work PC rebooted to install an update, then Edge came up instead of Firefox, but with all my Firefox tabs. I guess this was part of some effort to try to trick old people who wouldn't notice the difference into switching to Edge. Here's a news article about someone else running into this when it started happening: https://www.theverge.com/24054329/microsoft-edge-automatic-c...
"Old" people? How about the vast majority of the public, which is not represented on HN?
Not to mention that one of the many major UI regressions in Windows is the removal of title bars from application windows, which is fundamental to this "trick." Try opening a PDF in Edge and also in Acrobat. Neither window has a title bar, and they are otherwise almost identical. You have to scrutinize the very few controls around the window to determine which app you're looking at.
Microsoft and its software are trash now.