Outlook 2021 Stops Responding/Freezes

One more thing:  if the simple answer is to just recreate the Outlook profile, will I lose content doing so.  I have another machine also running Outlook with the same content.  Maybe it just gets picked up from there?

I have multiple email accounts established (both through Exchange online and via GMail)

Google Workspace account?

No  Google workspace account.  I  renamed the ost files for each of my exchange accounts. Then when Outlook restarted it was forced to create new ost files.  So far so good.  Fingers crossed though.  Thank you.

The new ost file approach described above did not work for long.  So, I uninstalled Office 2021 completely and reinstalled it.  Not sure if that will work and if it does not I will delete (rename) all of the ost files, uninstall, reinstall and try again.

Not sure where to go from there.  Any other comments appreciated.

After you have reinstalled Outlook 2021, do not add back the email accounts immediately.

Run a Windows update instead and make sure that everything is updated before you add back the email accounts. Make sure you have deleted all .OST files before you add back the email accounts.

OK.  Thanks.

My thanks for your help, Jackie.  I have fixed Outlook after a couple of days of work on it.  I am still not sure what the problem was but it is back to working the way I need it to.  For the record, in case I face this again, and as a preamble to closing this case, I thought I would recap everything below.  

I made extensive use of an excellent piece by Andrew Leinart.  It suggested and helped me through much of what follows: https://www.experts-exchange.com/articles/36072/Troubleshoot-and-Fix-Outlook-Problems.html.  In a couple of places below, I abbreviated my process, and Andrew' piece has the details

THE RECAP:
I am running Outlook 2021 (Office Professional Plus 2021) through domains on my Office 365 account.  The O/S is Windows 10 64 bit - completely updated. Outlook 2021 freezes regularly: initially when I try to read emails and now when I try to reconfigure the profiles.

To deal with this I:
a) Removed add-ins,
b) Emptied all deleted folders,
c) Ran the Microsoft Support and Recovery Assistant several times (one note here - I eventually answered "no" every time the question "is it fixed" was asked. Sometimes I could not tell and I wanted to force it to perform all of the maintenance tasks) ,
d) Ran Outlook Advanced Diagnostics,
e) Prevented external content in the trust settings,
f) Ran repair functions through control panel (both Quick and Online),
g) Ran scanpst on all ost files and accepted the recommended repairs
h) Ran chkdsk,
i) Ran sfc /scannow,
j) Ran DISM
k) Ran virus scans
l) Rebooted several times
m) Installed updated drivers for video card and monitors
n) Uninstalled and reinstalled Office 2021 with new profiles

I have multiple email accounts established (both through Exchange online and via GMail).  This seemed not to be the issue as they have all worked fine until now.

Two things that I should have looked at, and if the problem occurs again, I guess I will have to:
1) I have a lot of folders in a couple of the mail accounts - I may need to rationalize those better.  For now, they are very handy in organizing my practice. (See https://docs.microsoft.com/en-US/outlook/troubleshoot/performance/performance-issues-if-too-many-items-or-folders)

2) A Microsoft support person suggested turning off or ratcheting Cached Exchange mode.  My setting is "on" for all of these accounts and I store all of the contents since I often work outside my office and/or offline  

MY CONJECTURE ON WHAT HAPPENED AND WHAT WORKED:
I think the profiles were corrupted and it seems like step g) above did not completely fix that.  Completely uninstalling Office (step n) and/or running the Support and Recovery Assistant (step c) seems to have fixed that.  But, it was then a huge job tweaking Outlook back to how I had it set up.

I hope this helps someone else.  It has been a long grind but (fingers crossed again) I think that's it.