A couple of weeks ago I upgraded my 2017 MacBook Air to Sonoma 14.5. It’s not officially supported: MacOS support for my machine was due to run out in September with no more security updates.
Result - it’s working great! Even faster than Monterey (although that will in part be because I did a clean install). I obviously can’t take advantage of every feature in Sonoma due to not having an M series chip, but that’s fine. I get that! I do, however, have a copy of Safari that will be updated going forward, an OS that now has security updates for a long while yet, and some cool new (to me) features like continuity camera, web apps, desktop widgets and some mail improvements.
I totally get the commercial decisions behind Apple’s decisions, but given Sonoma works perfectly (unlike my attempts to get Windows to run on a Chromebook!), it’s a pity Apple don’t still support these machines officially.
Why specifically were they dropped? At some point all Intel devices will be dropped from updates, and that’s understandable, but until then… it seems to me to be purely planned obsolesce from a supposedly “green” corporation. It’s not like they don’t make money from me from being part of their ecosystem!
Generally there is some (perhaps obscure) piece of hardware in the device which is no longer supported. It is likely that you don’t use the features that rely on that hardware, or rarely use them and simply haven’t noticed yet. For example, a some years back some models were dropped because they had an old Wifi card which was no longer supported. However, if you were using a hardwired ethernet connection that might not matter to you. Other years the unsupported hardware has been more noticeable, like support for a specific video card; but even then, if the Mac is being used headless, maybe that wouldn’t affect everyone. However, Apple seems to avoid regressions in hardware support by simply no longer supporting that model at all.
I have a 2014 MacBook Air, and the software I had used for eclipse photography did not work with the OS I had on the machine, and despite promises was not updated in time for the April TSE in the US. I found a newer application, but it was needed a version of the OS that was not supported by the hardware.
OpenCore allowed me to update to the minimum required OS, and I was able to use the software to drive the camera via script to photograph the eclipse.
As @waylan notes, there may be issues, and thus I wouldn’t use it on my daily driver. But for this use case it was just what I needed.
“Unsupported” doesn’t mean “won’t work” - it means “we don’t guarantee it will work,” or “you won’t have a good experience.” And most importantly, it always means, “we don’t want to hear about your problems if it doesn’t.”
I personally think it’s pretty cool that the hardware lasts long enough that this actually becomes an issue.
