MS Outlook too Slow on Mac

I may have found a fix to this problem.  I believe the Keychain entries for Office were corrupt, duplicative or otherwise problematic.

Fix:

I open one of the Office apps (Word in my case) and signed out completely from Office 365 and OneCloud (I have a personal account as well as an Office 365 OnceCloud account).

I closed Word (no Office apps are now open).  I opened Keychain Access, searched for any entries in Keychain with the word "microsoft" in it.  I had several entries related to Office and OneDrive/Office 365.  I deleted all of them.

I opened Word again, signed into Office 365/OneDrive.  I then opened each of the other Office 2016 apps (Excel, PowerPoint, OneNote; I do not use Outlook but open it, too, if you do) one at a time.  In each instance the icon will bounce in the Dock for a quite a bit then a dialog box will appear asking you to allow access to a keychain entry (multiple entries if you are signed into multiple accounts like me); reply "always allow" to each dialog box request and the app will finish opening.

After doing this for each Office app (and closing each app), I opened each app again and the time to launch was significantly shorter; in fact, what I would call "normal".

I rebooted my Mac and launched Office apps again.  This time no app requested keychain access and each launched quickly.  The second launching was very fast indeed.

I recognize this may not be the root cause for everyone's posted issue, but I hope this approach may help others.  In any case, it does not assume you use an AV application or anything at all. Period.  Every Mac uses Keychain, so this is likely a fix that can work for may people who have slow app launch issues.