The average lifespan of a desktop is five years, and for a laptop, 3-5. All of you bitching about how computers older than ten years old not being supported is some massive injustice are completely divorced from reality in the marketplace.
Apple provides security updates for the prior two releases, which means that damn near any Mac made in the last ten years, even without Opencore Legacy, is still receiving security updates.
My 2013 Macbook Pro will run the current MacOS release with Opencore Legacy. That's a now-ten-year-old computer running the current OS release.
Anyone who uses their computer for a significant period of time, and especially to make money, who does not upgrade more quickly than every ten years, isn't very smart. It doesn't take long, waiting for your computer every day, before it's costing you more in lost productivity than it would be to replace it with something newer, especially if you buy used.
Claiming that a ten year old laptop, Apple or otherwise, is "perfectly usable" is a joke by people who clearly haven't spent any appreciable time using current hardware, which is by every single measure enormously better.
They have for phones but I think they could do better when it comes to the computers.
Also it would be nice to have a formal statement of what their intentions are.
As an example I have no idea how long my four year old Mac Mini will continue to get updates for.