In the days before the internet, software was designed, built and tested before being released. Changes were infrequent because they involved disks or CDs being distributed, so it was easier to get it right the first time. Now we have moved to subscription systems, automatically updated via the internet, and things have changed. Updates are constant, I suspect because testing is poor and bugs more frequent. Additionally, because of the subscription charges, software companies feel the need to keeping changing things to give the impression that the subscription is worthwhile...
Sadly in many cases, such as this, the changes have no value to many/most users, and if not actually deleterious are merely a distraction and something new to adjust to for no good reason. For me, this change falls into this category. For years (I've been using Outlook since the early 90's) I've known exactly how to do the things I need to do. Recently there have been several changes (search etc.) that are either detrimental or pointless to me, given my use of the product. This is another such change. For the next little while I'll go to the wrong place every time I want to view my calendar, be momentarily annoyed and wish for the days when I installed software from a CD and it stayed that way until I decided to change it.
I remember a MS presentation back in the 90's, where they said that they had developed the Office software functionality as far as they could go, and from then forward they would largely be working to improve the user experience. I wonder if they've now simply confused "improve" with "change"......
The other thing that interests me is that I saw the "preview" to this change and stayed with the old version. In these days of "user activity tracking" I assume MS watched many people do the same thing, yet they still chose to force the change on everyone.......