Yes it has - https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/lin...

Of course some (many) people are using forks, but all sync directly or indirectly with this dude's version.

You are mistaken.

Linux kernel dev branch single source of truth is https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/lin...

The stable branches have their single source of truth repositories, too.

I think replying to "it doesn't have a single source of truth" with "actually there are multiple single sources of truth" kind of makes the OP's case for them.

What are you saying??

There is a single source of truth for a particular version of Linux.

I'm saying, you're wrong, and trying to wriggle out of being wrong by redefining the statement.

Before I read the other responses, I assumed it was just Linus’ personal repo

Same here.

A few days ago I read about the multiple Linux distributions that all have their fork with special patches etc. pp.