I have a WiFi only version of the IPad Air 2. I bought it new in 2015 and it’s amazing that Apple continued to support it with operating system upgrades this long. It runs 15 perfectly.
Sadly it will not receive iPadOS 16 which will be released later this year.
We’ve had a good run! I’ve read on a couple of tech sites that Apple will sometimes continue to release security updates for devices that can’t receive full operating system upgrades. Not really ready to get a replacement at this time so I’m hoping this is true!