Open up the hamburger menu, you'll see games, shopping comparisons, etc. It feels like 90s adware. I'm not surprised they're turning PDF reading into a paid advertisement for Acrobat.
I switched to Edge on Mac from Chrome this week for one reason and one reason only: In full screen, Edge properly displays the addressbar when the cursor is moved to the top of the screen, while Chrome still cannot do this. (No, I do not want to enable "Always Show Toolar in Full Screen".) My understanding is that this is a very, very, very longstanding entry in Chrome's bugzilla.
The transition was easy; Edge even handled extensions correctly, pulling extensions from the Edge store when possible (except when versions differ, which I noticed in two cases) and from the Chrome store for the rest. Even extension settings came over. The only flaw I saw was that Edge only imported tabs from one Chrome window; I had to bookmark all tabs in each window, reimport bookmarks into Edge, then reopen each set of bookmarks into its own window.
Also saw something new recently: got some “tips” in some sort of in-browser notification drawer, again asking to be set as default. Apparently denying synchronous dialogs as you open the browser aren’t enough, you should get nagged asynchronously as well.
Of course, when you check out their recent Bing Chat, you’ll be asked to set the entire Microsoft suite as default, plus installing their mobile apps, so that you can be bumped up in a completely opaque waiting list.
I switched to Edge and Bing a few years ago and don't at all regret it. Switching was painless, the browser uses much less CPU on windows, it syncs across all devices including mac, all the chrome extensions still work, and search results on bing are better than google in my testing.
Afaik Windows doesn’t ship with a default PDF viewer other than Edge’s, so they probably made a pretty sweet deal with Adobe to let them in to upsell their subscription.