I can also run modern Linux distributions on 20 year old hardware.

The "landfill" comment was likely just about how software support periods have become so short, meaning for the current crop of computing devices (including actual computers, phones, tablets) the hardware itself almost always outlasts the company's support period for official software updates, which is disgraceful. I have drawers full of old phones that turn on, display is perfect/bright, battery is reasonably strong, can connect to WiFi, everything works, except the company threw their arms up and gave up on software support.

Windows 10 was released in July 2015 and is currently set to receive updates until October 2025. That's a little over 10 years.

And with previous generations of Windows there was nothing really stopping you from upgrading to a newer OS on the same old hardware - although you might run into serious performance issues with a modern Windows OS on 10+ year old hardware. But you could also switch to plenty of other OSes. I assume that's also an option for 7+ year old Macs?

XP got patches for so long just because many many governments and very large corporations convinced microsoft to keep extending it.

I'm not really seeing a big enough difference between 7 and 10 years to call one ownership and the other leasing to be honest

by the same metric the iPhone 5s still got some patches even this year [1], which makes it "supported" for 10 years

[1]: https://support.apple.com/en-en/HT213597

…so it still has a hard stop, just 3-4 years further into the future?