*Not an endorsement, nor do I have experience with this company or product other than a recent good support contact. I think I may have found my new mail client for my 40Gb of archived mails and many folders. I'm optimisitic.
Search for "eM Client".
Go to site and look at Downloads, and version history, and Mac. A version 9 beta for Mac was just posted. eM support indicated v9 has improved Outlook importing. Free 30 day. Free for non-commercial use, 2 mail accounts. $50. one-time for Pro version app.
I exported from Outlook to a OLM file to an external drive, as I didn't have enough storage space on my MacBook Air M1.
I used eM Client v9 to import from that OLM file.
Searches are working in the eM Client app and found emails are sorted in a date view correctly. (When I tried version 8, there was a problem. Their support advised me to wait and try version 9.
I'll update this post, but it may not be today. I'm sure it'll take me time to adjust to it. I've been with Entourage and Outlook for 15+ years.