https://arstechnica.com/gadgets/2021/11/apple-discontinues-21-5-inch-imac-with-intel-cpu/

Apple has discontinued the 21.5-inch iMac. The Intel-powered Mac's demise means that the only remaining iMacs are now the colorful, M1-equipped 24-inchers and the 27-inch version, which is still on Intel.

As reported by MacRumors on Saturday, Apple confirmed that it has discontinued the 21.5-inch iMac. This news comes after the removal of several configurations of the iMac in March and dwindling supply in April. The 21.5-inch iMac is no longer available from Apple's online or physical Apple stores unless you get a refurbished one. You may still be able to find unused machines at third-party sellers, MacRumors noted.