I have the same problem. So slow its unusable. It often crashes and the spinning ball comes up all the time. My iMac is 2015 updated with Monerey 12.5.1. Ive tried Etre and its say that my Hard Drive is too slow. Do I need a new computer?
This is probably an iMac with a Rotational / Mechanic Drive or a Fusion drive contains a Rotational Drive plus an SSD that is understood by the Operating System as one drive.
This assertion above would show up the excellent suggestion by @Old Toad to post the Etrecheck Report in full.
Should that be a fact and you what to extend the usable life of this machine ?
Invest in a good Enclosure and a good SSD Drive for the enclosure with enough Drive Capacity.
The install Monterey directly to the External Drive and make the External your Startup Drive
Good place to on-line shop would bewww.owc.com and they may have drive and Enclosure that best match your machine.
Post the entire report as directed above.
iMac crashes often and the spinning ball comes up all the time
