Outlook client in Windows 10 uses IE 11 as default browser? Really?

I just ran Outlook for the first time. I always use the web-based version of Outlook because it just works.

But I needed to test an HTML email in Outlook.

I was amazed how badly my email looked and how much had been stripped out by a program running in Windows 10 in 2019.

I clicked the notice telling me the email might look better if I view it in a web browser. It opened IE 11. 

There are no words.

How could a Microsoft product be directing people to IE when they have been pushing so hard to move everyone to Edge? Is it IE or Edge? Sounds like even Microsoft cannot decide.

The email did look a little better in IE11 than in the Outlook client. A little.