Is my iMac too old to keep updating?
My iMac updated to macOS High Sierra 10.13.6 in July 2018. Since then I've not been offered a new OS ( understand at least one if not two - Mojave and Catalina, perhaps - have been released. Why have they not come to my iMac? I download every new update sent. Are Apple trying to make me buy yet another iMac? Is this even a tiny bit good for the planet to keep buying hardware??? Can someone help, please?
iMac 21.5″, macOS 10.13