I was using Advanced Find just a few hours ago to manually archive email that was received prior to a particular date, since the auto-archive function was overlooking many messages due to its insistence on looking at the modified date instead of the received
date. I went into the other room for a few hours and watched a horror movie about an insane asylum, and when I came back I thought I was losing my own mind, because "Advanced Find" had disappeared. It's as if Outlook was trying to gaslight me by choosing
that moment to update. :-)
In any case, I fortunately remembered that you can get just about the same functionality, including pretty much the same criteria box that Advanced Find used, by creating a custom search under "Search Folders". I hope they don't decide to take that
away too, at least until they bring the "new and improved" search features up to par.
Also, I wonder if the fact that "Advanced Find" was "little used" has anything to do with the fact that they practically hid it ever since they added the quick search feature. I'm pretty sure it used to be available on the right-click menu for folders in
some version long ago. Now you have to click in the quick search box to turn on the otherwise-invisible "Search" ribbon, and even then it's buried under the "Search Tools" dropdown, instead of having a place directly on the ribbon -- which, by the way, has
plenty of additional room.
I really think Microsoft also needs to take into consideration that some of the most powerful features in any program are often little used, because they tend to be used by more advanced users, and particularly in special cases where nothing else will do.
It's usually OK to replace a powerful feature with something more streamlined that is capable of being equally powerful, but it's not OK to replace it with something that's more streamlined but less powerful.