>It's a computer I paid over £3,000 for, that got cut off 7 years after release
"after release" isn't even the metric we should be using. Rather we should measure starting from when the machine is _no longer sold_. Take the "Mac Pro 2013" (aka Trash Can Mac). It was introduced in 2013 but for sale by Apple until December 2019. macOS 13 Ventura, released October 2022, dropped support for it. That's only 3 years of support!
Whatever Microsoft offers. Or occasionally Linux. Which are usually considerably better than the support lengths Apple offers. For example Windows 7 was supported for over 10 years, 8/8.1 for over 10 years. They also don't tend to sell the same model for literally years.
Linux is a totally different story. “Linux” doesn’t support anything. It’s a kernel and doesn’t remove things out of tree so comparability is rarely removed so you could build things. But user space / distros and binary drivers can be a different beast (DKMS helps). Anyway. Linux is choose your own adventure and not comparable.
For Windows you’re not comparing the same thing. Apple ships a new major OS release on a yearly cadence compared with Microsoft’s 7 years. Some people might prefer Microsoft’s approach. People buying into the Apple ecosystem understand Apple takes a different approach. Also Microsoft isn’t your one stop shop for support. While Windows may be supported for 7 years, i doubt your OEM is supporting your firmware for that long. Apple ties firmware to operating system so that is easier to understand.
"after release" isn't even the metric we should be using. Rather we should measure starting from when the machine is _no longer sold_. Take the "Mac Pro 2013" (aka Trash Can Mac). It was introduced in 2013 but for sale by Apple until December 2019. macOS 13 Ventura, released October 2022, dropped support for it. That's only 3 years of support!