Yeah it's absurd. I have the 2.6GHz Quad Core 2012 Mac Mini (the top spec CPU), with 16GB RAM and an SSD. It destroys the 2014 Mac Mini, which they still support. It destroys the 2013 MacBook Air, which they still support.
So a 2012 rMBP with a quad core i7 and a GT 650M is not good enough, but a 1.1ghz dual core Intel core M and Intel graphics in a MacBook is fine.
I have a Late-2013 iMac, 27 inch.
Upgraded it with 32GB of RAM and 1TB SSD. It's still lightning-fast. No way in hell this is unsupported at the same time the 2012 model is unsupported!
All in all, this machine cost me 3000 CAD. Seven years later, buying the same specs from Apple would cost me 3500 CAD. Apple definitely has increased prices throughout the years, and used the Retina Displays as an excuse.
Why do people always think software support is tied to performance only? That's not (usually) how it works. In most cases it's some incompatibility that has little to do with raw power. Otherwise, why aren't you demanding Big Sur still support, say, the 2008 Mac Pro since it's more powerful than a 2019 MacBook Air?
Btw, increased prices? You know Inflation is a thing?
My guess is on the Nvidia card. It seems that they have giving up on doing Nvidia drivers altogether.
That can't be the reason, since the late 2013 and mid 2014 15" MBP with Nvidia 750M are still supported, while the late 2013 iMac with the same GPU isn't. There must be something else.
Yes it's due to the WiFi card installed the earlier 12/13 iMacs have the BCM94331 while the 14/15 iMacs all have the BCM94360 I'm sure an unsupported Mac OS installer will fix this issue for you.
Also can't be the (only) reason, since late 2013 iMacs too have the 4360 and are not supported.
Oh no my iMac just got old!
Oh hey, we have the exact same model/configuration! Sad to see such a capable machine unsupported by Big Sur, but then again 8 years is a good run, 10 years if you count security patches..
I'd just like to understand how this rather peculiar pattern of supported Macs comes into being. Can't (only) be GPU architecture or WiFi chip, since iMacs and MBPs from late 2013 don't differ in that.
On the other hand I'm surprised to see iPad Air 2 and even iPad mini 4 still supported on iOS 14. Would rather have it the other way round, but I'm not complaining.