how? my macbook pro is seven years old, and the latest macOS i could get is two major versions behind. I've tried installing linux and apparently it is a generation that is particularly troubled, with an endless list of broken things curated on github. eventually bad Bluetooth- and no internal audio-support was a showstopper to keep using it
It’s a 2015 Mac book pro that runs Monterey which still has update support. Getting new versions isn’t really important, getting support and updates is all that matters. I expect them to drop Monterey support at the end of this year which will be about a 10 yr service life. That seems pretty good to me. I have never had a windows laptop last 10yrs. And even at its age it is surprisingly pleasant to use with Mac OS.
Regarding Linux support, I started with Mint and everything works but the WiFi is a little slow. It looks like there has been some work to address that but I haven’t had time to try it out. It might be my favorite laptop I’ve ever had and it was only $100.
Apple locks old devices out of updates, although it takes about 10 years to do so. And after that, you can still do a workaround. Only problems is going to be when the last intel mac isn't going to be supported anymore, then the old devices will definitely be locked out.
Dropping support for older platforms happens for a number of reasons, including hardware-level security problems and lack of interest for ongoing maintenance. Linux distributions even drop support for older hardware. Even the Linux kernel itself has dropped support. A decision to not keep supporting a piece of hardware is not the same as preventing updates.
The thing to focus on isn't that Apple halts maintaining its own OSes on older hardware. Rather, we should press hardware makers and regulators on the boot loader locks and other obstacles that prevent end users from installing alternate OSes, especially once hardware makers end OS support for hardware. E.g., older iPads that can't run modern iPadOS but could easily run a lightweight Linux distribution. This applies to more than just Apple, like some Android devices. "Internet of Things" devices are similarly affected -- Belkin halted support for a generation of Wemo smart plugs when a vulnerability came out -- they told consumers to buy new Wemos and provided no alternate path for the older, still functional plugs.