I recently bought a 2012 Mini off ebay and found out i'm limited to 10.15.7!!! I think its the same CPU as the 2014 model that can run Monterey. Am I missing something?
You don't say which model you have, but I believe the 2012 Mini is Ivy Bridge and the 2014 is Haswell. You can see for yourself by looking at specific models here.
But it doesn't matter anyway, Apple typically bases support on the year in which a device was discontinued. The 2012 Mini was discontinued in 2014 but the 2014 Mini was sold until 2018.
Mac mini 2012 is Ivy Bridge with HD 4000 iGPU, Thunderbolt 1 and n-WiFi
Mac mini 2014 is Haswell with Iris 5100 iGPU, Thunderbolt 2 and ac-WiFi
Either return it or use OpenCore Legacy Patcher (unofficial way to get Big Sur/Monterey installed)
Mac mini 2012 is Ivy Bridge with HD 4000 iGPU, Thunderbolt 1 and n-WiFi
Mac mini 2014 is Haswell with Iris 5100 iGPU, Thunderbolt 2 and ac-WiFi
Either return it or use OpenCore Legacy Patcher (unofficial way to get Big Sur/Monterey installed)