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Microsoft begins cracking down on people dodging Windows 11's system requirements
(www.xda-developers.com)
This is a most excellent place for technology news and articles.
Apple supports current macOS plus the previous two. If he's on one of those ( which it sounds like) everything will work just fine.
The point was that Windows is the same.
All you've said is that it's fine because you can run Windows 10 on old hardware, but somehow being able to run a fully supported version of macOS isn't good enough.