Email Archiving has changed in Outlook 365

I run a Windows 10 desktop which has Microsoft Office 365 installed.  This is an individual subscription, there's no "administrator" except me.  I use the Outlook client for email, and for years I've used their "archive" process to move all email older than 1/1/<current year> to an archive.pst file.  Since I only do it once a year, my memory of the process is a little fuzzy, but I recall that I just opened an item called Clean Up Old Items (in the Toolbox under Account Information).  That tool shows a list of all the folders in my account, and I chose the top item and said "archive".  And it ran for quite a while and produced an archive file with last year's email and calendar in it.

I tried it this year and I cannot get it to run.  More accurately, it says "archiving" in the bottom bar, appears to be doing something for not very long, and then stops. 

My main Outlook.PST file is 3.38GB.  The archive file which the process produced is 2.19 MB and seems to be empty (I tried to open it).  These file sizes have not changed since the first time I ran the archive process, a couple of days ago.  I think I've tried it 3-4 times and gotten no visible results.  Previous annual archive files have been 1-3 GB.

I tried to look into Microsoft help and got a lot of discussion of automatic archiving, which I don't want to do.  I just want to put all the 2023 email and calendar files in a .pst file that I can use if I need it.  Can anyone explain to me in simple English what Microsoft is up to?  If this is off topic for this forum, can someone refer me to the correct Microsoft help files or help site?

Hi, they are trying to push things to on-line.      If Outlook Client is the built in email that comes with Windows it is being phased out for Outlook on-line if my understanding of something I do not use is correct.

This will give someone something to read

Keyword search : Microsoft Office 365 outlook archive    : https://www.google.com/search?client=firefox-b-d&q=Microsoft+Office+365+outlook+archive  I do not hunt for most stuff I do not use as am not always on target for Outlook/Office.

Windows 10 Outlook client for email end of life : https://www.google.com/search?client=firefox-b-d&q=Windows+10+Outlook+client+for+email+end+of+life