> Windows 10 was released in 2015. Apple releases a new major macOS update every year. Not really surprised that you can run 6 year old software + minor updates on an 6-10 year old machine but can't run a major software revision from the past couple years.

If you're saying that Windows 10 from 2021 is Windows 10 from 2015 with "minor updates", you haven't been paying attention to Windows updates :-)

Windows 10 updates are probably bigger than MacOS updates.