As a data point, I still use a 2013 Mac Pro as my primary desktop, and I've been using Sonoma on it for several months, have been able to install all Sonoma patches over-the-air on release without incident, and have only experienced a single, trivial problem: the right side of the menu bar occasionally appears shaded red, in a way that doesn't affect usability; switching applications immediately resolves the problem (the problem appears to be correlated with video playback).
Not just that, for high res stuff or modern codecs like AV1 or h265 is probably not supported at all in a 2012 device without updates for so long?
Even if support was possible it would be software encoding and even short clip it can take hours to render ?
I would happily use an older device for development a lot of dev work especially if not frontend or UI usually i can use any laptop just as a terminal, but UI or video editing I wouldn’t be able to.
I recently upgraded from a 2019 Intel Mac to a similarly-specced M3 Mac, and it really is night and day. My battery life is more than doubled - I can run IntelliJ and multiple Docker containers on battery for more than my whole work day, when before it would barely last a couple hours with that load and be slow while doing so. The fan hardly ever runs while on my Intel Mac it would run constantly.
Battery life, portability, COOL. Like, my actual lap is no longer burning.
But beyond that they are also incredibly fast and run cool. In the MacBook Air there is no fan and on the Pros they barely ever spin up in an audible way.
During work from home during Covid I was still using an Intel MBP and video conferences invariably caused the fans to kick up to the point where using noise cancelling headphones and not the built in speakers was necessary for sanity.
I think it's saving me an hour a day and the fan has never come on, the the laptop has never felt warm, and the battery life is just mind blowing.
I run docker & compilers all day. The i9 would run the fan 75% of the time and had to throttle down any time it was on battery power and it was lucky to last 3 hours on battery.
It is much, much faster, silent, and I use it for days without power. Editing 4K video is not just possible, it is a non event.