Note: Because of dependency on architecture and system changes to any current version of Apple operating systems (for example, macOS 26, iOS 26 and so on), not all known security issues are addressed in previous versions (for example, macOS 15, iOS 18 and so on).
macOS receives 1 year of full support and 2 additional years for security updates for each version with 6-8 years of upgrade eligibility. Windows 10 received 10 years of support (on top of a free upgrade from Windows 7/8.1 for most users).
I'm not sure why you're counting the years of support for a version of the OS and not the years of support for a computer. The interesting thing is: if you bought a computer at year X, does it still receive updates at X+Y?
There's loads of relatively young computers which can't upgrade to Windows 11 and therefore aren't supported anymore. That's the problem, not how long Windows 10 was supported.
