From all his public complaining about failing an interview it seems Google did the right thing not hiring him, he has a massive ego and it's very possible that "writing homebrew" is less useful to google than "inverting a binary tree"
There's not a more pragmatic measure of whether somebody can code than a track record of a successful code project used by other coders.
I'd say that if Linus applied to be a software engineer at Google they should be prepared to invert binary trees or do $generic_leetcode type things because that's the expectation for that role
If they applied to be Google Fellow or some other lofty position then I wouldn't expect them to need to do any coding at all in the interview
So the higher the role in Google the less the requirements?