I have one of the last Intel Macs and works perfectly fine (on Sonoma). How long should I expect working tech being supported?

I am already looking at Linux, but still need to get out of the Apple ecosystem. I am not going to spend +2500 Euros every 5 years on a laptop

Sonoma will be getting its last security update imminently (possibly tomorrow).

What does saying "working tech" do for you? If I have a working Samsung CRT from 25 years ago do I ping them about smart TV support? Nowadays it's a shitty situation with planned obsolescence; but 6 years for an open source project dedicating resources to a dead end is more than enough and appreciated.