It seems to be a common trend with Windows to make software worse before eventually bringing back old features. Take Skype, for example. It became nearly unusable for five years, losing 70% of its user base. Now, they've finally restored the functionality of the old Skype, but unfortunately, everyone has already moved on. It's quite amusing in its own way.
They appear to be doing the same thing with the new Outlook. They've removed much of the functionality to make it more web-based, catering to users who might prefer simpler interfaces. Why not just include an option to toggle an advanced version? This way, they could accommodate both users who favor simplicity and those who appreciate more robust features. It's frustrating to see them strip down software and remove functionalities that many value.
I doubt we'll see these functionalities return anytime soon, which is quite sad for longtime power users.